Answer:
In think the answer is 42,000
Step-by-step explanation:
Final answer:
To determine how many people will be drinking Coke in Turlock five weeks from now, multiply the percentage of Coke drinkers (60%) by the town's population (70,000). This gives us 0.60 * 70,000 = 42,000 people drinking Coke.
Explanation:
The question involves a numerical problem where we have to determine how many people will be drinking Coke in Turlock five weeks from now if the current population is 70,000 and 60% of them drink Coke. To find the answer, we simply need to calculate 60% of 70,000.
Calculation steps:
Convert 60% to a decimal by dividing 60 by 100, which gives us 0.60
Multiply 0.60 by the total population of Turlock, which is 70,000
The calculation will be 0.60 * 70,000
Now, let's do the calculation:
0.60 * 70,000 = 42,000
Therefore, if the population of Turlock stays constant at 70,000 and the cola drinking habits remain the same, approximately 42,000 people will be drinking Coke five weeks from now.
The time in seconds that it takes for a sled to slide down a hillside inclined at an angle θ is given by the formula below, where d is the length of the slope in feet. Find the time it takes to slide down a 2000 ft slope inclined at 30°. (Round your answer to one decimal place.) t = d 16 sin θ
Answer: It takes 15.8 seconds to slide down a 2000 ft slope.
Step-by-step explanation:
Since we have given that
[tex]t=\sqrt{\dfrac{d}{16\sin\theta}}[/tex]
where, t is the time taken,
d is the length to slide down a slope
sin θ is the angle at which it inclined.
So, we have d = 2000 ft
θ = 30°
So, the time taken is given by
[tex]t=\sqrt{\dfrac{2000}{16\sin 30^\circ}}\\\\t=\sqrt{\dfrac{2000}{8}}\\\\t=\sqrt{250}\\\\t=15.81\ seconds[/tex]
Hence, it takes 15.8 seconds to slide down a 2000 ft slope.
The time it takes to slide down a 2000 ft slope inclined at 30° is 250 seconds, calculated using the equation t = d / (16 sin θ).
Explanation:We're given the equation for calculating time of a sled sliding down a slope as t = d / (16 sin θ). Here, d is the length of the slope, and θ is the incline of the hill slope.
To calculate the time it takes to slide down a 2000 ft slope inclined at 30°, we substitute the respective values into the formula: t = 2000 / (16 sin 30). The sin value for 30° is 0.5, so the formula simplifies to t = 2000 / (16 * 0.5), which yields t = 2000 / 8. By performing that division, we see that t = 250 seconds. Therefore, it takes 250 seconds to slide down a 2000 ft slope inclined at 30°.
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Listed below are the lead concentrations in mug/g measured in different traditional medicines. Use a 0.01 significance level to test the claim that the mean lead concentration for all such medicines is less than 17 mug/g. 13 21 3.5 18.5 21.5 8.5 15.5 19 9 5.5
There is no significant difference in mean lead concentration for the medicines.
Hypothesis means an assumption or a claim which is needed to be tested.
To test the following hypothesis:
[tex]Null\ hypothesis,H_0: \mu=17\\Alternative\ Hypothesis,\ H_1: \mu < 17[/tex]
For the given data to test the hypothesis, t statistics can be used as follows:
[tex]t=\dfrac{\bar{X}-\mu}{\sigma}[/tex]
Given, Mean, μ=17
We are required to sample mean and σ in the excel table shown
below:
t=(17-13.05)/6.23
t=0.634
Using excel function to calculate p value of the t statistics as follows:
=T.DIST(0.634,9,1)
p=0.729
Since, p value is greater than level of significance 0.01. We fail to reject the null hypothesis and conclude that there is no significant difference in mean.
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To test the claim, calculate the mean and standard deviation of your sample data, set up your null and alternative hypotheses, calculate your test statistic t, reference a t-distribution table and compare your calculated t with the critical t-value.
Explanation:To test the claim that the mean lead concentration for all such medicines is less than 17 mug/g, we'll use a one-sample t-test because we have one sample present and we're comparing it to a known mean. Here are the steps:
First, calculate the mean and standard deviation of your sample data. For the given data set, you'll sum up all the values and then divide by the number of values to find the mean. Then, use the formula for standard deviation.Second, set up your null (H0) and alternative (H1) hypotheses: H0: The mean is greater than or equal to 17 mug/g. H1: The mean is less than 17 mug/g.Next, you need to calculate your test statistic t, using the formula t = (sample mean - hypothesized mean)/(standard deviation/square root of sample size (n)).Referencing a t-distribution table, check what the critical t-values is at 0.01 significance level with degree of freedom = n-1.If the calculated t is less than the critical t-value, we reject the null hypothesis. If it's greater, we do not reject the null hypothesis.Remember, rejecting the null hypothesis supports our claim that the mean concentration is less than 17 mug/g. Not rejecting the null hypothesis means that our data does not support the claim that the mean concentration is less than 17 mug/g, but it isn't proof that the concentration exactly equals to or exceeds 17 mug/g.
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The manager of a grocery store has taken a random sample of 100 customers. The average length of time it took the customers in the sample to check out was 3.1 minutes. The population standard deviation is known to be 0.5 minutes. We want to see if we can find significant evidence to prove that the mean waiting time of all customers is significantly more than 3 minutes. The test statistic is 2. What is the p-value? Round your answer to three decimal places.
Answer: The critical value is: insufficient.
Step-by-step explanation: Refer to Exhibit 9-2. The p-value is:
a. .0500
b. .0228
c. .0456
d. .0250
In order to test the hypotheses H0: μ ≤ 100 and Ha: μ > 100 at an α level of significance, the null hypothesis will be rejected if the test statistic z is:
The practice of concluding "do not reject H0" is preferred over "accept H0" when we:
a. have an insufficient sample size.
b. have not controlled for the Type II error.
c. are testing the validity of a claim.
d. are conducting a one-tailed test.
In hypothesis testing, the critical value is: insufficient
Isabella must take four 100-point tests in her math class. Her goal is to achieve an average grade of 95 on the tests. Her first two test scores were 97 and 91. After seeing her score on the third test, she realized she can still reach her goal. What is the lowest possible score she could have made on the third test?
Answer:
92
Step-by-step explanation:
She is taking four tests. She wants to average a 95 on those tests. Therefore, she must score 95*4=380 total. She scored 97 and 91, or 188 total. Therefore, she must score 380-188 = 192 total on her next two tests. Her maximum score possible on the fourth test is 100. Therefore, the lowest score possible for the third test would be 192-100=92
The lowest possible score Isabella could have made on the third test
is 92 marks.
What is a numerical expression?A numerical expression is a mathematical statement written in the form of numbers and unknown variables. We can form numerical expressions from statements.
Given, Isabella must take four 100-point tests in her math class and her goal is to achieve an average grade of 95 on the tests.
So, The total marks she needs to score in four games is (4×95).
= 380.
Now, She scores 97 and 91 in her first and second tests.
So, She needs to score
380 - (97 + 91)
= 380 - 188.
= 192 in her two tests.
Now, The highest marks she can score in the fourth test is 100.
Therefore, The lowest possible marks she can score is,
= 192 - 100.
= 92.
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According to a report from a business intelligence company, smartphone owners are using an average of 20 apps per month Assume that number of apps used per month by smartphone owners is normally distributed and that the standard deviation is 4. Complete parts (a) through (d) below. a. If you select a random sample of 36 smartphone owners, what is the probability that the sample mean is between 19.5 and 20.5? (Round to three decimal places as needed.)
Answer: 0.547
Step-by-step explanation:
As per given , we have
Population mean = [tex]\mu=20[/tex]
Population standard deviation= [tex]\sigma=4[/tex]
Sample size : n= 36
We assume that number of apps used per month by smartphone owners is normally distributed.
Let [tex]\overline{x}[/tex] be the sample mean.
Formula : [tex]z=\dfrac{\overline{x}-\mu}{\dfrac{\sigma}{\sqrt{n}}}[/tex]
The probability that the sample mean is between 19.5 and 20.5 :-
[tex]P(19.5<\overline{x}<20.5)\\\\=P(\dfrac{19.5-20}{\dfrac{4}{\sqrt{36}}}<\dfrac{\overline{x}-\mu}{\dfrac{\sigma}{\sqrt{n}}}<\dfrac{20.5-20}{\dfrac{4}{\sqrt{36}}})\\\\=P(-0.75<z<0.75)\\\\=P(z<0.75)-P(z<-0.75)\ \ [\because P(z_1<z<z_2)=P(z<z_2)-P(z<z_1)]\\\\=P(z<0.75)-(1-P(z<0.75))\ \ [\because P(Z<-z)=1-P(Z<z)]\\\\=2P(z<0.75)-1=2(0.7734)-1=0.5468\approx0.547[/tex]
[using standard normal distribution table for z]
Hence, the required probability = 0.547
To find the probability that the sample mean is between 19.5 and 20.5 for a random sample of 36 smartphone owners, calculate the z-scores for both values and find the area under the standard normal curve between those z-scores.
Explanation:To find the probability that the sample mean is between 19.5 and 20.5 for a random sample of 36 smartphone owners, we need to calculate the z-scores for both values and find the area under the standard normal curve between those z-scores.
The formula for calculating the z-score is: z = (x - μ) / (σ / √n), where x is the sample mean, μ is the population mean, σ is the standard deviation, and n is the sample size.
Using the given information, the z-scores for 19.5 and 20.5 are: z1 = (19.5 - 20) / (4 / √36) = -0.75 and z2 = (20.5 - 20) / (4 / √36) = 0.75.
Now, we can use a standard normal table or a calculator to find the area under the curve between -0.75 and 0.75. The probability is approximately 0.467.
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A researcher would like to estimate p, the proportion of U.S. adults who support recognizing civil unions between gay or lesbian couples. If the researcher would like to be 95% sure that the obtained sample proportion would be within 1.5% of p (the proportion in the entire population of U.S. adults), what sample size should be used?
(a) 17,778(b) 4,445(c) 1,112(d) 67(e) 45
Answer:
(b) 4,445
Step-by-step explanation:
If the researcher would like to be 95% sure that the obtained sample proportion would be within 1.5% of p (the proportion in the entire population of U.S. adults), what sample size should be used?
Given a=0.05, |Z(0.025)|=1.96 (check standard normal table)
So n=(Z/E)^2*p*(1-p)
=(1.96/0.015)^2*0.5*0.5
=4268.444
Take n=4269
Answer:(b) 4,445
Scott has run 11/8 miles already and plans to complete 16/8 miles. To do this, how much farther must be run?
Scott needs to run 5/8 miles more.
Step-by-step explanation:
Distance covered = 11/8 miles
Total distance = 11/8 miles
Distance left to cover = Total distance - Distance covered
[tex]Distance\ left\ to\ cover= \frac{16}{8}-\frac{11}{8}\\Distance\ left\ to\ cover=\frac{16-11}{8}\\Distance\ left\ to\ cover=\frac{5}{8}[/tex]
Scott needs to run 5/8 miles more.
Keywords: distance, subtraction
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Evaluate ModifyingBelow Integral from nothing to nothing With Upper C xy dx plus (x plus y )dy along the curve y equals 2 x squared from (1 comma 2 )to (2 comma 8 ).
[tex]y=2x^2\implies\mathrm dy=4x\,\mathrm dx[/tex]
Then in the integral we have
[tex]\displaystyle\int_Cxy\,\mathrm dx+(x+y)\,\mathrm dy=\int_1^2(2x^3+4x(x+2x^2))\,\mathrm dx=\int_1^210x^3+4x^2\,\mathrm dx=\boxed{\frac{281}6}[/tex]
You are designing a 1000 cm^3 right circular cylindrical can whose manufacture will take waste into account. There is no waste in cutting the aluminum for the side, but the top and bottom of radius r will be cut from squares that measure 2r units on a side. The total amount of aluminum used up by the can will therefore beA = 8r^2 + 2pi rhWhat is the ratio now of h to r for the most economical can?
Answer:
h /r = 2.55
Step-by-step explanation:
Area of a can:
Total area of the can = area of (top + bottom) + lateral area
lateral area 2πrh without waste
area of base (considering that you use 2r square) is 4r²
area of bottom ( for same reason ) 4r²
Then Total area = 8r² + 2πrh
Now can volume is 1000 = πr²h h = 1000/πr²
And A(r) = 8r² + 2πr(1000)/πr²
A(r) = 8r² + 2000/r
Taking derivatives both sides
A´(r) = 16 r - 2000/r²
If A´(r) = 0 16 r - 2000/r² = 0
(16r³ - 2000)/ r² = 0 16r³ - 2000 = 0
r³ = 125
r = 5 cm and h = ( 1000)/ πr² h = 1000/ 3.14* 25
h = 12,74 cm
ratio h /r = 12.74/5 h /r = 2.55
To find the ratio of h to r for the most economical can, we need to minimize the amount of aluminum used. The ratio is 0.
Explanation:To find the ratio of h to r for the most economical can, we need to minimize the amount of aluminum used. The total amount of aluminum used is given by the equation A = 8r^2 + 2πrh. To minimize A, we can take the derivative of A with respect to h and set it equal to 0. Solving this equation will give us the value of h in terms of r, and we can then find the ratio of h to r.
Taking the derivative of A with respect to h, we get dA/dh = 2πr. Setting this equal to 0 and solving for h, we find that h = 0. To find the ratio of h to r, we divide both sides of the equation by r, giving us h/r = 0.
Therefore, the ratio of h to r for the most economical can is 0.
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A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of six hours, what is the required sample size if the error should be less than a half hour with a 95% level of confidence?
Answer:
Sample size should be atleast 55320
Step-by-step explanation:
Given that a group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week.
population standard deviation [tex]\sigma = 6 hrs[/tex]
Std error = [tex]\frac{6}{\sqrt{n} }[/tex]
Margin of error for 95%
= [tex]1.96*\frac{6}{\sqrt{n} } <0.5\\\sqrt{n} >235.2\\n \geq 55319.04[/tex]
Since sample size is number of items it cannot be indecimal.
So we can round off to the next high integer on a safer side.
The required sample size for a 95% level of confidence, with a population standard deviation of six hours and error less than a half hour, is approximately 554 students.
Explanation:
The question is about finding the required sample size for a statistics project. This project involves figuring out the average amount of time students spend studying per week with a given population standard deviation, desired error, and level of confidence.
To solve this, we use the formula for sample size: n = [(Z_α/2*σ)/E]^2. Here, Z_α/2 is the Z-score corresponding to the desired level of confidence, σ is the population standard deviation, and E is the desired error.
For a 95% level of confidence, the Z-score is about 1.96 (you can find this value in Z-tables). Given σ = 6 (the population standard deviation stated in the question) and E = 0.5 (the desired error less than a half hour), we substitute these into the formula to get:
n = [(1.96*6)/0.5]^2
So, n ≈ 553.29. Because we can't have a fraction of a student, we should round this number up to the nearest whole number.
Therefore, "the required sample size is 554 students".
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Write an equation of the line passing through the point (3, -1) and parallel to the line y=2/3x - 5. Show work
Answer:
The answer is: y = 2/3x - 3
Step-by-step explanation:
Given point: (3, -1)
Given equation: y = 2/3x - 5, which is in the form y = mx + b where m is the slope and b is the y intercept.
Parallel lines have the same slope. Use the point slope form of the equation with the point (3, -1) and substitute:
y - y1 = m(x - x1)
y - (-1) = 2/3(x - 3)
y + 1 = 2/3x - 6/3
y + 1 = 2/3x - 2
y = 2/3x - 3
Proof:
f(3) = 2/3(3) - 3
= 6/3 - 3
= 2 - 3
= -1, giving the point (3, -1)
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Suppose that the insurance companies did do a survey. They randomly surveyed 400 drivers and found that 320 claimed they always buckle up. We are interested in the population proportion of drivers who claim they always buckle up. Construct a 95% confidence interval for the population proportion who claim they always buckle up. What is the error bound?
Answer:
The 95% confidence interval would be given (0.761;0.839). The error bound is [tex]Me=\pm 0.0392[/tex]
Step-by-step explanation:
1) Data given and notation
n=400 represent the random sample taken
X=320 represent the people drivers claimed they always buckle up
[tex]\hat p=\frac{320}{400}=0.8[/tex] estimated proportion of people drivers claimed they always buckle up
[tex]\alpha=0.05[/tex] represent the significance level (no given, but is assumed)
Confidence =95% or 0.95
p= population proportion of people drivers claimed they always buckle up
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
2) Calculating the interval for the proportion
The confidence interval would be given by this formula
[tex]\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}[/tex]
For the 95% confidence interval the value of [tex]\alpha=1-0.95=0.05[/tex] and [tex]\alpha/2=0.025[/tex], with that value we can find the quantile required for the interval in the normal standard distribution.
[tex]z_{\alpha/2}=1.96[/tex]
And replacing into the confidence interval formula we got:
[tex]0.8 - 1.96 \sqrt{\frac{0.8(1-0.8)}{400}}=0.761[/tex]
[tex]0.8 + 1.96 \sqrt{\frac{0.8(1-0.8)}{400}}=0.839[/tex]
And the 95% confidence interval would be given (0.761;0.839). The error bound is [tex]Me=\pm 0.0392[/tex]
We are confident that about 76.1% to 83.9% of people drivers that they always buckle up at 95% of confidence
A group of 24 people have found 7.2 kg of gold. Assuming the gold is divided evenly, how much gold will each one get in grams? Please someone help me out with this thank you
Answer:
300 g
Step-by-step explanation:
There are 1000 grams in one kilogram. Dividing 7200 grams into 24 equal parts makes each part ...
(7200 g)/(24 persons) = 300 g/person
Each person get 300 grams.
USA Today reported that about 47% of the general consumer population in the United States is loyal to the automobile manufacturer of their choice. Suppose Chevrolet did a study of a random sample of 1006 Chevrolet owners and found that 490 said they would buy another Chevrolet. Does this indicate that the population proportion of consumers loyal to Chevrolet is more than 47%? Use alpha = 0.01.
Answer: No, It does not indicates that the population proportion of consumers loyal to Chevrolet is more than 47%.
Step-by-step explanation:
Let p denotes the proportion of consumers loyal to Chevrolet.
As per given , we have
[tex]H_0: p=0.47\\\\ H_a: p>0.47[/tex]
Since the alternative hypothesis [tex](H_a)[/tex] is right-tailed so the test would be a right-tailed test.
Also , it is given that ,Chevrolet did a study of a random sample of 1006 Chevrolet owners and found that 490 said they would buy another Chevrolet.
i.e. n = 1006
x= 490
[tex]\hat{p}=\dfrac{490}{1006}=0.487[/tex]
Test statistic :
[tex]z=\dfrac{\hat{p}-p}{\sqrt{\dfrac{p(1-p)}{n}}}[/tex]
, where p=population proportion.
[tex]\hat{p}[/tex]= sample proportion
n= sample size.
i.e. [tex]z=\dfrac{0.487-0.47}{\sqrt{\dfrac{0.47(1-0.47)}{1006}}}=1.08[/tex]
P-value (for right-tailed test)= P(z>1.08)=1-P(z≤1.08) [∵P(Z>z)=1-P(Z≤z)]
=1- 0.8599=0.1401 [By z-value table.]
Decision : Since p-value (0.14) is greater than the significance level ([tex]\alpha=0.01[/tex]) , it means we are failed to reject the null hypothesis.
Conclusion : We have sufficient evidence to support the claim that about 47% of the general consumer population in the United States is loyal to the automobile manufacturer of their choice.
Hence, it does not indicates that the population proportion of consumers loyal to Chevrolet is more than 47%.
Final answer:
There's sufficient evidence to support the claim that about 47% of the general consumer population in the United States is loyal to their chosen automobile manufacturer. Thus, it doesn't indicate that the population proportion of consumers loyal to Chevrolet is more than 47%.
Explanation:
Given:
Null hypothesis (H0): The proportion of consumers loyal to Chevrolet is 47%.
Alternative hypothesis (Ha): The proportion of consumers loyal to Chevrolet is greater than 47%.
Data:
Chevrolet conducted a study of a random sample of 1006 Chevrolet owners.
Among them, 490 said they would buy another Chevrolet.
Calculations:
Sample proportion [tex](\hat{p}) = 490/1006 ≈ 0.487[/tex]
Test statistic (z) = [tex](0.487 - 0.47) / \sqrt((0.47 * (1 - 0.47)) / 1006) \approx 1.08[/tex]
P-value calculation:
Since it's a right-tailed test, P-value = P(z > 1.08) = 1 - P(z ≤ 1.08).
Look up the value in the z-table to find P(z ≤ 1.08) ≈ 0.8599.
P-value ≈ 1 - 0.8599 ≈ 0.1401.
Decision:
Since the P-value (0.14) is greater than the significance level (α = 0.01), we fail to reject the null hypothesis.
There's sufficient evidence to support the claim that about 47% of the general consumer population in the United States is loyal to their chosen automobile manufacturer.
Thus, it doesn't indicate that the population proportion of consumers loyal to Chevrolet is more than 47%.
A manufacturer of chocolate chips would like to know whether its bag filling machine works correctly at the 418 gram setting. It is believed that the machine is underfilling the bags. A 9 bag sample had a mean of 411 grams with a standard deviation of 20 . A level of significance of 0.025 will be used. Assume the population distribution is approximately normal. Is there sufficient evidence to support the claim that the bags are underfilled?
Answer: There is sufficient evidence to support the claim that the bags are under-filled.
Step-by-step explanation:
Since we have given that
[tex]H_0:\mu=418\\\\H_a:\mu<418[/tex]
Sample mean = 411
Standard deviation = 20
n = 9
So, the test statistic value is given by
[tex]z=\dfrac{\bar{x}-\mu}{\dfrac{\sigma}{\sqrt{n}}}\\\\\\z=\dfrac{411-418}{\dfrac{20}{\sqrt{9}}}\\\\\\z=\dfrac{-7}{\dfrac{20}{3}}\\\\\\z=-1.05[/tex]
At 0.025 level of significance,
critical value z = -2.306
since -2.306<-1.05
so, we will reject the null hypothesis.
Yes, there is sufficient evidence to support the claim that the bags are underfilled.
Dan was trying to get faster at his multiplication tables. This table shows the time it took him to complete each of four tests containing 50 simple multiplication problems.
Which comparison of the time for each test is correct?
Test 1 < Test 4
Test 2 > Test 4
Test 1 > Test 3
Test 3 < Test 2
Answer:Test 1 < Test 4
Step-by-step explanation: Test 1 was easier so it took less time to complete the questions. As the tests continue they get harder meaning they will take more time to answer.
Answer:
the answer is a
Step-by-step explanation:
i just took the test
Consider the line integral Z C (sin x dx + cos y dy), where C consists of the top part of the circle x 2 + y 2 = 1 from (1, 0) to (−1, 0), followed by the line segment from (−1, 0) to (2, −π). Evaluate this line integral in two ways:
Direct computation:
Parameterize the top part of the circle [tex]x^2+y^2=1[/tex] by
[tex]\vec r(t)=(x(t),y(t))=(\cos t,\sin t)[/tex]
with [tex]0\le t\le\pi[/tex], and the line segment by
[tex]\vec s(t)=(1-t)(-1,0)+t(2,-\pi)=(3t-1,-\pi t)[/tex]
with [tex]0\le t\le1[/tex]. Then
[tex]\displaystyle\int_C(\sin x\,\mathrm dx+\cos y\,\mathrm dy)[/tex]
[tex]=\displaystyle\int_0^\pi(-\sin t\sin(\cos t)+\cos t\cos(\sin t)\,\mathrm dt+\int_0^1(3\sin(3t-1)-\pi\cos(-\pi t))\,\mathrm dt[/tex]
[tex]=0+(\cos1-\cos2)=\boxed{\cos1-\cos2}[/tex]
Using the fundamental theorem of calculus:
The integral can be written as
[tex]\displaystyle\int_C(\sin x\,\mathrm dx+\cos y\,\mathrm dy)=\int_C\underbrace{(\sin x,\cos y)}_{\vec F}\cdot\underbrace{(\mathrm dx,\mathrm dy)}_{\vec r}[/tex]
If there happens to be a scalar function [tex]f[/tex] such that [tex]\vec F=\nabla f[/tex], then [tex]\vec F[/tex] is conservative and the integral is path-independent, so we only need to worry about the value of [tex]f[/tex] at the path's endpoints.
This requires
[tex]\dfrac{\partial f}{\partial x}=\sin x\implies f(x,y)=-\cos x+g(y)[/tex]
[tex]\dfrac{\partial f}{\partial y}=\cos y=\dfrac{\mathrm dg}{\mathrm dy}\implies g(y)=\sin y+C[/tex]
So we have
[tex]f(x,y)=-\cos x+\sin y+C[/tex]
which means [tex]\vec F[/tex] is indeed conservative. By the fundamental theorem, we have
[tex]\displaystyle\int_C(\sin x\,\mathrm dx+\cos y\,\mathrm dy)=f(2,-\pi)-f(1,0)=-\cos2-(-\cos1)=\boxed{\cos1-\cos2}[/tex]
The line integral of (sin x dx + cos y dy) over curve C is calculated using parameterization and direct computation for the circle part and the line segment part, or alternative methods such as polar coordinates or contour integration.
The question involves evaluating the line integral of the function (sin x dx + cos y dy) along a given curve C, which in this case consists of two parts: the upper semicircle of x2 + y2 = 1 and a line segment from (−1, 0) to (2, −π). To evaluate this, we use two methods: direct computation and using Green's theorem when applicable. For the semicircle, we parameterize it by setting x = cos(θ), y = sin(θ), where θ ranges from 0 to π. The line segment can be parameterized by a straight line equation derived from the two points. The integral along the curve is computed separately for each piece, and the results are added together to find the integral over the entire curve. To evaluate the line integral in an alternate method, one might use tricks such as transforming to polar coordinates or employing complex analysis techniques such as contour integration, depending on the nature of the integral.
Statistics can help decide the authorship of literary works. Sonnets by a certain Elizabethan poet are known to contain an average of μ = 8.9 new words (words not used in the poet’s other works). The standard deviation of the number of new words is σ = 2.5. Now a manuscript with six new sonnets has come to light, and scholars are debating whether it is the poet’s work. The new sonnets contain an average of x~ = 10.2 words not used in the poet’s known works. We expect poems by another author to contain more new words, so to see if we have evidence that the new sonnets are not by our poet we test the following hypotheses.
H0 : µ = 8.88 vs Ha : µ > 8.88
Give the z test statistic and its P-value. What do you conclude about the authorship of the new poems? (Let a = .05.)
Use 2 decimal places for the z-score and 4 for the p-value.
a. What is z?
b.The p-value is greater than?
c.What is the conclusion? A)The sonnets were written by another poet or b) There is not enough evidence to reject the null.
Answer:
We conclude that the sonnets were written by by a certain Elizabethan poet.
Step-by-step explanation:
We are given the following in the question:
Population mean, μ = 8.9
Sample mean, [tex]\bar{x}[/tex] =10.2
Sample size, n = 6
Alpha, α = 0.05
Population standard deviation, σ = 2.5
First, we design the null and the alternate hypothesis
[tex]H_{0}: \mu = 8.88\\H_A: \mu > 8.88[/tex]
We use One-tailed z test to perform this hypothesis.
a) Formula:
[tex]z_{stat} = \displaystyle\frac{\bar{x} - \mu}{\frac{\sigma}{\sqrt{n}} }[/tex]
Putting all the values, we have
[tex]z_{stat} = \displaystyle\frac{10.2 - 8.9}{\frac{2.5}{\sqrt{6}} } = 1.28[/tex]
Now, [tex]z_{critical} \text{ at 0.05 level of significance } = 1.64[/tex]
b) We calculate the p value with the help of z-table.
P-value = 0.1003
The p-value is greater than the significance level which is 0.05
c) Since the p-value is greater than the significance level, there is not enough evidence to reject the null hypothesis and accept the null hypothesis.
Thus, we conclude that the sonnets were written by by a certain Elizabethan poet.
The z-score is 1.86 and the p-value is 0.0314. As the p-value is less than the level of significance α (0.05), we reject the null hypothesis and conclude that the new sonnets were likely written by another author.
Explanation:In this statistical testing scenario for authorship of literary works, we need to find out the z-score or z test statistic and then determine the p-value to check if the new sonnets could be the works of the known Elizabethan poet or not.
For calculating the z score, you use the formula z = (x~ - μ) / (σ / √n) = (10.2 - 8.9) / (2.5/ √6) = 1.86 to two decimal places. The p-value is determined from the standard normal distribution table which for a z-score of 1.86 is 0.0314.
Given that α = 0.05, since the p-value is less than α, we reject the null hypothesis H0 (that the works were by the Elizabethan poet). Therefore, we accept the alternative hypothesis Ha (the sonnets were written by another author).
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10 kids are randomly grouped into an A team with five kids and a B team with five kids. Each grouping is equally likely.
(a) What is the size of the sample space?
(b) There are two kids in the group, Alex and his best friend Jose. What is the probability that Alex and Jose end up on the same team?
The size of the sample space for grouping 10 kids into two teams is 252. The probability of Alex and Jose being on the same team is 4/9.
To calculate the sample space for randomly grouping 10 kids into two teams of five, we consider the number of ways to choose 5 kids out of 10, since choosing the first team automatically determines the second. The size of the sample space is given by the combination formula C(n, k) = n! / (k!(n - k)!), where n! represents the factorial of n. Therefore, the sample space size is C(10, 5) = 10! / (5!5!) = 252.
To find the probability that Alex and Jose end up on the same team, we need to consider two scenarios: both in team A or both in team B. Since the order they are picked doesn't matter, they are one unit, and we need to choose 3 additional members for their team from the remaining 8 kids, we use the combination formula again: C(8, 3).
There are C(8, 3) ways for them to be on the same team and this can happen in two different teams. Thus, the probability that they are on the same team is (2 * C(8, 3)) / C(10, 5).
Calculating this gives us (2 * 56) / 252, which simplifies to 112/252, and reduces to 4/9 when simplified. So, the probability is 4/9.
The populations, P, of six towns with time t in years are given by
1) P=2400(0.8)^t
2) P=900(0.77)^t
3)P=2100(0.98)^t
4)P=600(1.18)^t
5)P=1100(1.08)^t
6)P=1700(1.191)^t
Answer the following questions regarding the populations of the six towns above. Whenever you need to enter several towns in one answer, enter your answer as a comma separated list of numbers. For example if town 1, town 2, town 3, and town 4, are all growing you could enter 1, 2, 3, 4 ; or 2, 4, 1, 3 ; or any other order of these four numerals separated by commas.
(a) Which of the towns are growing?
(b) Which of the towns are shrinking?
(c) Which town is growing the fastest?
What is the annual percentage growth RATE of that town? %
(d) Which town is shrinking the fastest?
What is the annual percentage decay RATE of that town? %
(e) Which town has the largest initial population?
(f) Which town has the smallest initial population?
Answer:
Since, in the population function,
[tex]P = ab^t[/tex]
a = initial population,
b = population change factor,
If 0 < b < 1, then population will shrink,
While, if b > 1, then the population will grow,
(a) Since, 1.18, 1.08 and 1.191 is greater than 1,
Thus, town 4), 5) and 6) are growing.
(b) Since, 0.8, 0.77 and 0.98 are less than 1,
Thus, town 1), 2) and 3) are shrinking.
(c) An exponential growth function with highest change factor grows fastest.
∵ 1.191 > 1.18 > 1.08
⇒ town 6) is growing fastest.
(d) An exponential decay function with lowest change factor shrinks fastest,
∵ 0.77 < 0.8 < 0.98 < 1.08 < 1.18 < 1.191,
⇒ Town 2) shrinks fastest.
(e) Since,
2400 > 2100 > 1700 > 1100 > 900 > 600
⇒ town 1) has the largest initial population.
(f) Similarly,
Town 4) has the smallest initial population.
Answer:
a.
i, ii, and iv
Step-by-step explanation:
A survey of 1010 college seniors working towards an undergraduate degree was conducted. Each student was asked, "Are you planning or not planning to pursue a graduate degree?" Of the 1010 surveyed, 658 stated that they were planning to pursue a graduate degree. Construct and interpret a 98% confidence interval for the proportion of college seniors who are planning to pursue a graduate degree. Round to the nearest thousandth.
Answer:
The 98% confidence interval would be given (0.616;0.686).
We are confident at 98% that the true proportion of people that they were planning to pursue a graduate degree is between (0.616;0.686).
Step-by-step explanation:
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
Description in words of the parameter p
[tex]p[/tex] represent the real population proportion of people that they were planning to pursue a graduate degree
[tex]\hat p[/tex] represent the estimated proportion of people that they were planning to pursue a graduate degree
n=1010 is the sample size required
[tex]z_{\alpha/2}[/tex] represent the critical value for the margin of error
The population proportion have the following distribution
[tex]p \sim N(p,\sqrt{\frac{p(1-p)}{n}})[/tex]
Numerical estimate for p
In order to estimate a proportion we use this formula:
[tex]\hat p =\frac{X}{n}[/tex] where X represent the number of people with a characteristic and n the total sample size selected.
[tex]\hat p=\frac{658}{1010}=0.651[/tex] represent the estimated proportion of people that they were planning to pursue a graduate degree
Confidence interval
The confidence interval for a proportion is given by this formula
[tex]\hat p \pm z_{\alpha/2} \sqrt{\frac{\hat p(1-\hat p)}{n}}[/tex]
For the 98% confidence interval the value of [tex]\alpha=1-0.98=0.02[/tex] and [tex]\alpha/2=0.01[/tex], with that value we can find the quantile required for the interval in the normal standard distribution.
[tex]z_{\alpha/2}=2.33[/tex]
And replacing into the confidence interval formula we got:
[tex]0.651 - 2.33 \sqrt{\frac{0.651(1-0.651)}{1010}}=0.616[/tex]
[tex]0.651 + 2.33 \sqrt{\frac{0.651(1-0.651)}{1010}}=0.686[/tex]
And the 98% confidence interval would be given (0.616;0.686).
We are confident at 98% that the true proportion of people that they were planning to pursue a graduate degree is between (0.616;0.686).
Yahto and Nora want to find out if the quadrilateral formed by connecting points J, K, L, and M is a rectangle.
Yahto’s plan:
• Use the distance formula to find the lengths of the sides.
• Then see if the side lengths of opposite sides are the same.
Nora’s plan:
• Find the slopes of the four sides.
• See if the slopes of adjacent sides are negative reciprocals of each other.
Which student’s plan will work?
A. Both plans are correct.
B. Neither plan is correct.
C. Only Yahto’s plan is correct.
D. Only Nora’s plan is correct.
Answer:
B. Neither plan is correct
Step-by-step explanation:
Yahto has the right idea in that opposite sides of a rectangle are the same length. However, that is also true of a parallelogram that is not a rectangle. The condition Yahto is looking for is necessary, but not sufficient.
__
Nora's plan will discover if adjacent sides are perpendicular to each other, provided that the slopes are defined in each case. Her plan will not work in the event there are vertical sides with undefined slope. Any quadrilateral in which all adjacent pairs of sides form right angles will be a rectangle.
_____
Strictly speaking, neither plan is completely correct. Yahto can discover rectangles that Nora cannot, and Nora can determine quadrilaterals are not rectangles when Yahto would improperly classify them.
_____
Comment on showing a quadrilateral is a rectangle
My favorite plan is to show the diagonals are the same length and have the same midpoint: J+L = K+M; ║J-L║ = ║K-M║.
Both Yahto and Nora's plans make sense, but only Nora's plan will always correctly determine if a quadrilateral is a rectangle. This is because finding negative reciprocal slopes confirms perpendicular, or right, angles which are necessary for a shape to be a rectangle.
Explanation:Both Yahto and Nora have good strategies, but only Nora’s plan will always lead to the correct identification of a rectangle. A rectangle is defined as a quadrilateral with four right angles. While having equal length of opposite sides is a property of rectangles, it is not exclusive to rectangles. It can also be true for other quadrilaterals, such as parallelograms and rhombuses.
On the other hand, Nora's plan relies on finding negative reciprocal vertices, which is in line with a property of rectangles – adjacent sides are perpendicular. In a coordinate plane, if two lines are perpendicular, the slopes of the lines are negative reciprocals of each other. Hence, if these conditions are met, it would confirm that the quadrilateral is a rectangle.
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You were given the following joint probability function for
Y1 = { 0, if the child survived, 1, if not,
and
Y2 = { 0 if no belt used, 1 if adult belt used, and 2 if car seat belt used
Notice that Y1 is the number of fatalities per child and, since children's car seats usually utilize two belts, Y2 is the number of seat belts in use at the time of accident.
Given:
Y1
y2 0 1 total
0 0.38 0.17 0.55
1 0.14 0.02 0.16
2 0.24 0.05 0.29
Total 0.76 0.24 1
Are Y1 and Y2 independent? Why or why not?
Answer: No, Y1 and Y2 are not independent
Step-by-step explanation:
Because they don't satisfy this condition:
FsubscriptY1Y2(Y1,Y2) = FsubscriptY1(y1) × FsubscriptY2(y2)
... for all given values of Y1 and Y2
This is the condition for independence.
How do we know that Y1 and Y2 don't satisfy this condition?
We use the information in the Joint Probability Distribution Table.
Let's see if the condition stands when Y1 is zero and Y2 is zero
FsubscriptY1Y2(0,0) = 0.38
FsubscriptY1(0) × FsubscriptY2(0) = 0.76×0.55 = 0.418
We can see that 0.38 is not equal to 0.418
Doing the test for any other combination of Y1 and Y2 values will give unequal figures as well.
Pedro thinks that he has a special relationship with the number 3. In particular, Pedro thinks that he would roll a 3 with a fair 6-sided die more often than you'd expect by chance alone. Suppose p is the true proportion of the time Pedro will roll a 3.
(a) State the null and alternative hypotheses for testing Pedro's claim. (Type the symbol "p" for the population proportion, whichever symbols you need of "<", ">", "=", "not =" and express any values as a fraction e.g. p = 1/3)
H0 = _______
Ha = _______
(b) Now suppose Pedro makes n = 30 rolls, and a 3 comes up 6 times out of the 30 rolls. Determine the P-value of the test:
P-value =________
Answer:
p value = 0.3122
Step-by-step explanation:
Given that Pedro thinks that he has a special relationship with the number 3. In particular,
Normally for a die to show 3, probability p = [tex]\frac{1}{6} =0.1667[/tex]
Or proportion p = 0.1667
Pedro claims that this probability is more than 0.1667
[tex]H_0 = P =0.1667______H_a = P>0.1667_____[/tex]
where P is the sample proportion.
b) n=30 and [tex]P = 6/30 =0.20[/tex]
Mean difference = [tex]0.2-0.1667=0.0333[/tex]
Std error for proportion = [tex]\sqrt{\frac{p(1-p)}{n} } \\=0.0681[/tex]
Test statistic Z = p difference/std error = 0.4894
p value = 0.3122
p >0.05
So not significant difference between the two proportions.
The null hypothesis is that Pedro's claim is not true, while the alternative hypothesis is that Pedro's claim is true. The P-value is approximately 0.082.
Explanation:
(a) The null hypothesis states that Pedro's claim is not true, so the null hypothesis is H0: p = 1/6. The alternative hypothesis states that Pedro's claim is true and he rolls a 3 more often than expected, so the alternative hypothesis is Ha: p > 1/6.
(b) To determine the P-value, we can use the binomial distribution. The probability of rolling a 3 with a fair 6-sided die is 1/6. Using the binomial distribution, we can calculate the probability of rolling a 3 six times out of 30 rolls. This gives a P-value of approximately 0.082, which is the probability of observing a result as extreme as the one obtained or more extreme, assuming the null hypothesis is true.
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Suppose X, Y, and Z are random variables with the joint density function f(x, y, z) = Ce−(0.5x + 0.2y + 0.1z) if x ≥ 0, y ≥ 0, z ≥ 0, and f(x, y, z) = 0 otherwise. (a) Find the value of the constant C. (b) Find P(X ≤ 1.375 , Y ≤ 1.5). (Round answer to five decimal places). (c) Find P(X ≤ 1.375 , Y ≤ 1.5 , Z ≤ 1). (Round answer to six decimal places).
a.
[tex]f_{X,Y,Z}(x,y,z)=\begin{cases}Ce^{-(0.5x+0.2y+0.1z)}&\text{for }x\ge0,y\ge0,z\ge0\\0&\text{otherwise}\end{cases}[/tex]
is a proper joint density function if, over its support, [tex]f[/tex] is non-negative and the integral of [tex]f[/tex] is 1. The first condition is easily met as long as [tex]C\ge0[/tex]. To meet the second condition, we require
[tex]\displaystyle\int_0^\infty\int_0^\infty\int_0^\infty f_{X,Y,Z}(x,y,z)\,\mathrm dx\,\mathrm dy\,\mathrm dz=100C=1\implies \boxed{C=0.01}[/tex]
b. Find the marginal joint density of [tex]X[/tex] and [tex]Y[/tex] by integrating the joint density with respect to [tex]z[/tex]:
[tex]f_{X,Y}(x,y)=\displaystyle\int_0^\infty f_{X,Y,Z}(x,y,z)\,\mathrm dz=0.01e^{-(0.5x+0.2y)}\int_0^\infty e^{-0.1z}\,\mathrm dz[/tex]
[tex]\implies f_{X,Y}(x,y)=\begin{cases}0.1e^{-(0.5x+0.2y)}&\text{for }x\ge0,y\ge0\\0&\text{otherwise}\end{cases}[/tex]
Then
[tex]\displaystyle P(X\le1.375,Y\le1.5)=\int_0^{1.5}\int_0^{1.375}f_{X,Y}(x,y)\,\mathrm dx\,\mathrm dy[/tex]
[tex]\approx\boxed{0.12886}[/tex]
c. This probability can be found by simply integrating the joint density:
[tex]\displaystyle P(X\le1.375,Y\le1.5,Z\le1)=\int_0^1\int_0^{1.5}\int_0^{1.375}f_{X,Y,Z}(x,y,z)\,\mathrm dx\,\mathrm dy\,\mathrm dz[/tex]
[tex]\approx\boxed{0.012262}[/tex]
(a) We determined the constant C by integrating the joint density function over the entire space, finding = 1/10.
(b) We calculated P(X≤1.375,Y≤1.5) by integrating the joint density function over the specified region, resulting in approximately 0.1286.
(c) For P(X≤1.375,Y≤1.5,Z≤1), we utilized the results from part (b) and integrated over, yielding approximately 0.1163.
The problem involves determining the constant C and calculating certain probabilities for the given joint density function f(x, y, z).
Below is the step-by-step solution:
Part (a): Finding the Constant C
First, we need to find the value of C such that the total probability is 1.
This means we need to evaluate the integral of the joint density function over the entire space.
We solve the integral:[tex]\int \int \int C e^{-(0.5x + 0.2y + 0.1z)} \, dx \, dy \, dz = 1[/tex], where x, y, z ≥ 0
Breaking it down, we integrate one variable at a time:[tex]\int_{0}^{\infty} Ce^{-0.5x} \, dx = \frac{C}{0.5}[/tex]
[tex]\int_{0}^{\infty} e^{-0.5x} \, dx = \frac{1}{0.5}[/tex] from 0 to ∞ = 2C
Similarly, integrating for y and z:[tex]\int_{0}^{\infty} e^{-0.2y} \, dy = \frac{1}{0.2} = 5[/tex]
[tex]\int_{0}^{\infty} e^{-0.1z} \, dz = \frac{1}{0.1} = 10[/tex]
Thus, the overall integral is:2C * 5C * 10C = 1
100C³ = 1
C = 1 / 10
Part (b): Finding P(X ≤ 1.375 , Y ≤ 1.5)
We need to compute the double integral of the joint density function for X and Y:P(X ≤ 1.375 , Y ≤ 1.5) = [tex]\int_{0}^{1.375} \int_{0}^{1.5} 0.1 e^{-0.5x} e^{-0.2y} \, dy \, dx[/tex]
Evaluating the inner integral with respect to y first:[tex]\int_{0}^{1.5} e^{-0.2y} \, dy = -\frac{1}{0.2} (e^{-0.3} - 1)[/tex]
= [tex]\frac{1}{0.2} (1 - e^{-0.3}) = \frac{5}{3} (1 - e^{-0.3})[/tex]
= 5 * 0.2592
≈ 1.296
Now, integrating with respect to x:[tex]\int_{0}^{1.375} 0.1 \cdot 1.296 \cdot e^{-0.5x} \, dx = 0.1 \cdot 1.296 \cdot \left( 2 - 2 e^{-0.6875} \right)[/tex]
= [tex]0.1296 \cdot \left[ -2 e^{-0.5x} \right]_{0}^{1.375}[/tex]
= [tex]0.1296 \cdot 2 \cdot \left( 1 - e^{-0.6875} \right)[/tex]
= 0.1296 * 2 * (1 - 0.5038)
≈ 0.1296 * 2 * 0.4962
≈ 0.1286
Part (c): Finding P(X ≤ 1.375 , Y ≤ 1.5 , Z ≤ 1)
We need to compute the triple integral:P(X ≤ 1.375 , Y ≤ 1.5 , Z ≤ 1) = [tex]\int_{0}^{1.375} \int_{0}^{1.5} \int_{0}^{1} 0.1 e^{-0.5x} e^{-0.2y} e^{-0.1z} \, dz \, dy \, dx[/tex]
We already have the inner integrals for y and z from part (b):[tex]\int_{0}^{1} e^{-0.1z} dz = \left[ -\frac{1}{0.1} e^{-0.1z} \right]_{0}^{1}[/tex]
= [tex](1/0.1)(1 - e^{-0.1})[/tex]
= [tex]10 (1 - e^{-0.1})[/tex]
≈ 0.905
Combining all parts:
P(X ≤ 1.375 , Y ≤ 1.5 , Z ≤ 1) = 0.1286 * 0.905
≈ 0.1163
A sample of 30 distance scores measured in yards has a mean of 7, a variance of 16, and a standard deviation of 4. You want to convert all your distances from yards to feet, so you multiply each score in the sample by 3. What are the new mean, median, variance, and standard deviation?
Answer:
21, 144, 12
Step-by-step explanation:
Given that a sample of 30 distance scores measured in yards has a mean of 7, a variance of 16, and a standard deviation of 4.
Let X be the distance in yard.
i.e. each entry of x is multiplied by 3.
New mean variance std devition would be
E(3x) = [tex]3E(x) = 21[/tex]
Var (3x) = [tex]3^2 Var(x) = 9(16) =144[/tex]
Std dev (3x) = [tex]\sqrt{144 } =12[/tex]
Thus we find mean and std devition get multiplied by 3, variance is multiplied by 9
The new mean after converting the distances from yards to feet is 21, the median remains unchanged at 7, the new variance is 144, and the new standard deviation is 12.
To find the new mean, we multiply the original mean by the conversion factor. Since there are 3 feet in a yard, we have:
New Mean = Original Mean × Conversion Factor
= 7 yards × 3 feet/yard
= 21 feet
The median is a measure of central tendency that represents the middle value of a data set. When each data point is multiplied by a constant factor, the median is also multiplied by that factor. However, since the median is the middle value of an ordered list of data, and we are not changing the order or adding or removing any data points, the median in terms of yards and feet is the same numerical value, even though the units are different:
New Median = [tex]Original Median Ã[/tex]— Conversion Factor
= 7 yards (since the median is the same numerical value)
For the variance, when each data point is multiplied by a constant, the variance is multiplied by the square of that constant:
New Variance = [tex]Original Variance × (Conversion Factor)^2[/tex]
= [tex]16 yards^2 × (3 feet/yard)^2[/tex]
= [tex]16 yards^2 × 9 (feet^2/yard^2)[/tex]
= [tex]144 feet^2[/tex]
Finally, the standard deviation is the square root of the variance, so to find the new standard deviation, we take the square root of the new variance:
New Standard Deviation = [tex]√New Variance[/tex]
= [tex]√144 feet^2[/tex]
= 12 feet
Let D be the region bounded below by the plane zequals=0, above by the sphere x squared plus y squared plus z squared equals 900x2+y2+z2=900, and on the sides by the cylinder x squared plus y squared equals 100x2+y2=100. Set up the triple integrals in cylindrical coordinates that give the volume of D using the following orders of integration.
a. dz dr dthetaθ
b. dr dz dthetaθ
c. dthetaθ dz dr
Answer:
The cylinder is given straight away by x^2+y^2=r^2=16\implies r=4. To get the cylinder, we complete one revolution, so that 0\le\theta\le2\pi. The upper limit in z is a spherical cap determined by
x^2+y^2+z^2=144\iff z^2=144-r^2\implies z=\sqrt{144-r^2}
So the volume is given by
\displaystyle\iiint_{\mathcal D}\mathrm dV=\int_{\theta=0}^{\theta=2\pi}\int_{r=0}^{r=4}\int_{z=0}^{z=\sqrt{144-r^2}}r\,\mathrm dz\,\mathrm dr\,\mathrm d\theta
and has a value of \dfrac{128(27-16\sqrt2)\pi}3 (not that we care)
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Step-by-step explanation:
The probability that an individual without a college education earns more than $100,000 is 0.4, whereas the probability that a person with a B.S. or higher degree earns more than $100,000 is 0.6. The probability that a person chosen at random has a B.S. degree is 0.5. What is the probability that a person has at least a B.S. degree if it is known that he or she earns more than $100,000?
Answer:
0.6
Step-by-step explanation:
Given:
P( Person chosen at random has a B.S. degree), P(C) = 0.5
P( Person chosen at random does not have a B.S. degree), P(C') = 1 - 0.5 = 0.5
P(Student earns more than $100,000) = P(E)
P(Student earns more than $100,000, without going college) = P(E | C') = 0.4
P(Student earns more than $100,000, with college degree) = P(E | C) = 0.6
Now,
P(at least a B.S. degree | earns more than $100,000), P(C | E)
using Baye's theorem
we have
P(C | E) = [tex]\frac{P(C)\timesP(E | C)}{P(C)\timesP(E | C)+P(C')\timesP(E | C')}[/tex]
or
P(C | E) = [tex]\frac{0.5\times0.6}{0.5\times0.6+0.5\times0.4}[/tex]
or
P(C | E) = [tex]\frac{0.3}{0.5}[/tex]
or
P(C | E) = 0.6
To find the probability that a person has at least a B.S. degree if it is known that he or she earns more than $100,000, we can use Bayes' Theorem and the given probabilities.
Explanation:To find the probability that a person has at least a B.S. degree if it is known that he or she earns more than $100,000, we can use Bayes' Theorem. Let A be the event that the person has at least a B.S. degree, and let B be the event that the person earns more than $100,000. The probability of A given B can be calculated as:
P(A|B) = (P(B|A) * P(A)) / P(B)
Given that P(B|A) = 0.6, P(A) = 0.5, and P(B) = 0.4, we can substitute the values into the formula:
P(A|B) = (0.6 * 0.5) / 0.4 = 0.75
Therefore, the probability that a person has at least a B.S. degree if it is known that he or she earns more than $100,000 is 0.75.
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The article "Plugged In, but Tuned Out" (USA Today, January 20, 2010) summarized data from two surveys of randomly selected kids ages 8 to 18. One survey was conducted in 1999 and the other was conducted in 2009. Data on the number of hours per day spent using electronic media, consistent with summary quantities given in the article, are below.time1999<-c(4, 5, 7, 7, 5, 7, 5, 6, 5, 6, 7, 8, 5, 6, 6)time2009<-c(5, 9, 5, 8, 7, 6, 7, 9, 7, 9, 6, 9, 10, 9, 8)Find the 99% confidence interval for the difference between the mean number of hours per day spent using electronic media in 2009 and 1999. Show all steps of the confidence interval. You may use the formula or R for calculations.
Answer:
(-3.0486, -0.2848)
Step-by-step explanation:
Let the number of hours per day spent using electronic media from 1999 be the first population and the number of hours per day spent using electronic media from 1999 the second population.
We have small sample sizes [tex]n_{1} = 15[/tex] and
[tex]n_{2} = 15[/tex].
[tex]\bar{x}_{1} = 5.9333[/tex] and [tex]\bar{x}_{2} = 7.6[/tex]; [tex]s_{1} = 1.0998[/tex] and [tex]s_{2} = 1.5946[/tex].
The pooled estimate is given by
[tex]s_{p}^{2} = \frac{(n_{1}-1)s_{1}^{2}+(n_{2}-1)s_{2}^{2}}{n_{1}+n_{2}-2} = \frac{(15-1)(1.0998)^{2}+(15-1)(1.5946)^{2}}{15+15-2} = 1.8762[/tex]
The 99% confidence interval for the true mean difference between the mean number of hours per day spent using electronic media in 2009 and 1999 is given by
[tex](\bar{x}_{1}-\bar{x}_{2})\pm t_{0.01/2}s_{p}\sqrt{\frac{1}{15}+\frac{1}{15}}[/tex], i.e.,
[tex](5.9333-7.6)\pm t_{0.005}1.3697\sqrt{\frac{1}{15}+\frac{1}{15}}[/tex]
where [tex]t_{0.005}[/tex] is the 0.5th quantile of the t distribution with (15+15-2) = 28 degrees of freedom. So
[tex]-1.6667\pm(-2.7633)(1.3697)(0.3651)[/tex], i.e.,
(-3.0486, -0.2848)
######
Using R
time1999 <- c(4, 5, 7, 7, 5, 7, 5, 6, 5, 6, 7, 8, 5, 6, 6)
time2009 <- c(5, 9, 5, 8, 7, 6, 7, 9, 7, 9, 6, 9, 10, 9, 8)
n1 <- length(time1999)
n2 <- length(time2009)
(mean(time1999)-mean(time2009))+qt(0.005, df = 28)*sqrt(((n1-1)*var(time1999)+(n2-1)*var(time2009))/(n1+n2-2))*sqrt(1/n1+1/n2)
(mean(time1999)-mean(time2009))-qt(0.005, df = 28)*sqrt(((n1-1)*var(time1999)+(n2-1)*var(time2009))/(n1+n2-2))*sqrt(1/n1+1/n2)
To find the 99% confidence interval for the difference between the mean number of hours per day spent using electronic media in 2009 and 1999, we can use the formula: CI = (x1 - x2) ± Z * sqrt((s1^2/n1) + (s2^2/n2)). Using R, the 99% confidence interval for the difference between the mean number of hours per day spent using electronic media in 2009 and 1999 is (0.4733, 2.1933) hours.
Explanation:To find the 99% confidence interval for the difference between the mean number of hours per day spent using electronic media in 2009 and 1999, we can use the formula:
CI = (x1 - x2) ± Z * sqrt((s1^2/n1) + (s2^2/n2))
where x1 and x2 are the sample means, s1 and s2 are the sample standard deviations, n1 and n2 are the sample sizes, and Z is the critical value for a 99% confidence level.
Using R, we can calculate the confidence interval as follows:
time1999 <- c(4, 5, 7, 7, 5, 7, 5, 6, 5, 6, 7, 8, 5, 6, 6)The 99% confidence interval for the difference between the mean number of hours per day spent using electronic media in 2009 and 1999 is (0.4733, 2.1933) hours. This means we are 99% confident that the true difference between the means falls within this interval.
Learn more about confidence interval here:https://brainly.com/question/32278466
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The height of Jake's window is 5x - 3 inches and the width is 3x + 2 inches. What is the perimeter of Jake's window ?
Answer: (16x - 2)inches
Step-by-step explanation:
The shape of Jake's window is a rectangle. It means that the two opposite sides are equal. The perimeter of the rectangular window is the distance round it.
The perimeter of a rectangle is expressed as 2(length + width)
From the dimensions given
Length = height of the window
= 5x - 3 inches
Width = 3x + 2 inches
Perimeter of the window =
2(5x - 3 + 3x + 2) = 10x - 6 + 6x + 4
= 10x + 6x + 4 - 6
Perimeter of the window =
(16x - 2)inches
Answer:The perimeter of window can be calculated by the following formula;
Step-by-step explanation: