Answer:
[tex]Z = -2.865[/tex] means that it would be unusual to see 32% who rarely or never use academic advising services in one of these samples
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Z scores below -2 are considered unusually low.
Z scores above 2 are considered unusually high.
For a sample proportion p in a sample of size n, we have that [tex]\mu = p, \sigma = \sqrt{\frac{p(1-p)}{n}}[/tex]
In this problem, we have that:
[tex]\mu = 0.42, \sigma = \sqrt{\frac{0.42*0.58}{200}} = 0.0349[/tex]
Is it unusual to see 32% who rarely or never use academic advising services in one of these samples
What is the z-score for X = 0.32?
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{0.32 - 0.42}{0.0349}[/tex]
[tex]Z = -2.865[/tex]
[tex]Z = -2.865[/tex] means that it would be unusual to see 32% who rarely or never use academic advising services in one of these samples
No, it is not unusual to see 32% of students rarely or never using academic advising services in one of these samples.
Explanation:To determine if it is unusual to see 32% of students rarely or never using academic advising services in one of these samples, we can compare it to the range of values that would be considered usual. In this case, we can use the 95% confidence interval provided, which states that the true proportion of community college students who rarely or never use academic advising services is between 0.113 and 0.439. If the observed proportion falls within this interval, it would be considered usual; otherwise, it would be considered unusual.
Since 32% falls within the range of 0.113 and 0.439, it is considered a usual value. Therefore, it is not unusual to see 32% of students rarely or never use academic advising services in one of these samples.
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. If Triangle ABC is equilateral, solve for X... *
7 (8x - 44)
Answer:
x=13
Step-by-step explanation: (8x-44)+(8x-44)+(8x-44)=180
24x-132=180
24x=312
312/24
x=13
Showing Proof
8(13)-44=60
60+60+60=180
Therefore the answer is x=13
In the triangle in the given diagram, the value of x is 13
In the diagram, the value of ∠C = (8x -44)°.
To determine the value of x, we will first determine the measure of ∠C.
From the question,
Triangle ABC is equilateral
Recall that, each interior angle of an equilateral triangle equals 60°.
∴ m ∠C = 60°
Since the measure of ∠C = 60°
Then, we can write that
(8x - 44)° = 60°
Now, we will solve the above equation for x
8x° - 44° = 60°
First, add 44° to both sides
8x° - 44° + 44° = 60° + 44°
8x° = 104°
∴ x = 104° ÷ 8°
x = 13
Hence, in the given triangle, the value of x is 13
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Your Mutual Fund was valued at $237,500. It has lost 6% per year for the last 3 years. What is its value today?
a) $179,263.70
b) $187,721.40
c) $197,263.70
d) $237,500.60
Answer:
The answer is C) $197,263.70
Step-by-step explanation:
It's losing 6% PER year for the last 3 year.
You can do what I did and take $237,500 and times it 0.06. Which should give you 14,250, that is how much is lost in year one.
So subtract 14,250 from 237,500, you should have $223,250 now.
Repeat the first step with $223,250 now, you times it by 0.06 again and you should get 13,395, you subtract that from $223,250.
You have $209,855 now, once again times that by 0.06 and you get 12,591.30. Subtract 12,591.30 from 209,855 and you should end up with $197,263.70
It's a long, simple method and I'm sure there is another method of solving this question, but this is an easy way to get the answer.
Answer:
c
Step-by-step explanation:
because simple answer
In a math class there are 8 male students and 7 female students. A student is randomly selected to go to the front office and leaves. A second student is randomly selected to go to the office. What is the approximate probability that both students that left were male students? *
Final answer:
To find the probability of selecting two male students from a class with 8 male and 7 female students, we multiply the individual probabilities. Hence, the answer is 4/15.
Explanation:
Probability of getting a male student in the first selection: 8/15
Probability of getting a male student in the second selection given the first is male: 7/14
Probability both selections are male students: (8/15) * (7/14) = 8/30 = 4/15
At Cheng's Bike Rentals, it costs $36 to rent a bike for 9 hours.
How many hours of bike use does a customer get per dollar?
Answer:
4 hours
Step-by-step explanation:
what is the area of a rectangle that is 6 5/7 by 7 3/5
Answer:
51.0264 units squared
Step-by-step explanation:
1) convert the fractions into decimals.
5/7+6=6.714 and 3/5+7=7.6
2) Use the formula A=lw to find the area of the rectangle
[tex]6.714*7.6=51.0264[/tex]
What property is 7/8+0=7/8?
Answer:
wdym
Step-by-step explanation:
The equation 7/8 + 0 = 7/8 demonstrates the Identity Property of Addition, which states adding zero to any number leaves it unchanged. This property highlights zero's role as the addition identity element.
Explanation:The property illustrated by the equation 7/8 + 0 = 7/8 is known as the Identity Property of Addition. This property states that adding zero to any number or fraction does not change its value. It's an essential property in mathematics, underlining the concept that zero is the identity element for addition. This implies that adding zero to a number does not contribute any new value, essentially leaving the original number unchanged.
In broader mathematical contexts, understanding such properties helps in simplifying expressions and solving equations more efficiently. The identity property, similar to the concept of identity in multiplication (where multiplying by 1 leaves a number unchanged), plays a crucial role in developing more complex algebraic concepts and operations.
What is the slope of the line that’s contains the points (-2, 5)and (6,-3)?
Answer:
The slope is -1
Step-by-step explanation:
We can find the slope by using
m = (y2-y1)/(x2-x1)
= (-3-5)/(6 - -2)
= (-3-5)/(6+2)
= -8/8
-1
Rewrite the expression in the form 9^n
(9^3) (9^12)
Answer:
[tex] {9}^{15} [/tex]
Step-by-step explanation:
[tex]( {9}^{3} ) \times ( {9}^{12} ) = 9 {}^{3 + 12} = {9}^{15} \\ [/tex]
A newspaper took a random sample of 1,200 registered voters and found that 925 would vote for the Dem at candidate for governor. Is this evidence that more than % of the entire voting population would vote for the Democrat? Assume a Type I error rate of a = 0.05. What are H, and H ? Report a p-value, state what your decision is, and explain why
Answer:
The null hypothesis is represented as
H₀: p ≤ (3/4)
The alternative hypothesis is represented as
Hₐ: p > (3/4)
z = 1.65
p-value = 0.049471
The obtained p-value is less than the significance level at which the test was performed at. Hence, we reject the null hypothesis, accept the alternative hypothesis & say that there is significant evidence to conclude that more than (3/4) of the voting population would vote for the Democrat.
Step-by-step explanation:
The complete question is presented in the attached image to this answer.
For hypothesis testing, the first thing to define is the null and alternative hypothesis.
The null hypothesis plays the devil's advocate and usually takes the form of the opposite of the theory to be tested. It usually contains the signs =, ≤ and ≥ depending on the directions of the test. It usually maintains that random chance is responsible for the outcome or results of any experimental study/hypothesis testing.
While, the alternative hypothesis usually confirms the the theory being tested by the experimental setup. It usually contains the signs ≠, < and > depending on the directions of the test. It usually maintains that other than random chance, there are significant factors affecting the outcome or results of the experimental study/hypothesis testing.
For this question, the null hypothesis would be that there isn't significant evidence that that more than (3/4) of the entire voting population would vote for the Democrat. That is, the proportion of the entire voting population that would vote for the democrat is less than or equal to (3/4).
While the alternative hypothesis is that there is significant evidence that more than (3/4) of the voting population would vote for the Democrat.
Mathematically,
The null hypothesis is represented as
H₀: p ≤ (3/4)
The alternative hypothesis is represented as
Hₐ: p > (3/4)
To do this test, we will use the z-distribution because the sample size (1200) is large enough for the p-value for z-test statistic and the t-test statistic to approximately be equal.
So, we compute the z-test statistic
z = (x - μ)/σₓ
x = sample proportion of the surveyed registered voters that would vote for the democrat = (925/1200) = 0.77
μ = p₀ = The standard proportion that we're comparing against = (3/4) = 0.75
σₓ = standard error = √[p(1-p)/n]
where n = Sample size = 1200
σₓ = √[0.77×0.23/1200] = 0.01215
z = (0.77 - 0.75) ÷ 0.01215
z = 1.65
checking the tables for the p-value of this t-statistic
Significance level = 0.05
The hypothesis test uses a one-tailed condition because we're testing only in one direction (whether the proportion is greater than 0.75)
p-value (for z = 1.65, at 0.05 significance level, with a one tailed condition) = 0.049471
The interpretation of p-values is that
When the (p-value > significance level), we fail to reject the null hypothesis and when the (p-value < significance level), we reject the null hypothesis and accept the alternative hypothesis.
So, for this question, significance level = 0.05
p-value = 0.049471
0.171485 < 0.05
Hence,
p-value < significance level
This means that we reject the null hypothesis, accept the alternative hypothesis & say that there is significant evidence to conclude that more than (3/4) of the voting population would vote for the Democrat.
Hope this Helps!!!
During a recent drought, a water utility in a certain town sampled 100 residential water bills and found that 73 of the residences had reduced their water consumption over that of the previous year. f) If 95% confidence intervals are computed for 200 towns, what is the probability that more than 192 of the confidence intervals cover the true proportions
Final answer:
The probability of more than 192 confidence intervals containing the true proportion when constructing 95% confidence intervals across 200 towns, which follows a binomial distribution.
Explanation:
When constructing confidence intervals for a proportion, if we state that we have 95% confidence, this means that if we were to take many samples and build a confidence interval from each sample, we would expect 95% of those intervals to contain the population proportion. In the case with 200 towns, 95% confidence suggests that approximately 190 out of 200 intervals would contain the true population proportion, as 95% of 200 is 190.
To find the probability that more than 192 of these intervals contain the true proportion, we would use the binomial distribution, where each interval has a 0.95 probability of containing the true proportion (success), and we are looking for the sum of the probabilities of 193, 194, ..., 200 successes out of 200 trials.
At a concert, 825 out of the 1500 audience are female.
What percentage of the audience are female?
Answer:
55%
Step-by-step explanation:
You could first find
10% of 1500=150
50%=750
25%=525
5%=75
750+75=825
The answer is 55% are female
The percentage of the audience that are female at the concert is 55%. This is calculated by dividing the number of females (825) by the total audience number (1500), and then multiplying that result by 100.
Explanation:To calculate the percentage of women in the audience, we need to divide the number of women by the total number of people in the audience, then multiply by 100 to convert the decimal into a percentage.
The number of women is 825.The total number of people is 1500.Thus, the calculation would be as follows:
(825 / 1500) * 100 = 55%
So, the percentage of the audience that are female is 55%.
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Write a function that solves the matrix equation Ax = b using Gaussian Elimination (book section 6.2). Your function should accept as input a n-by-n matrix A and an n-by-1 vector b, and it should produce a n-by-1 vector x that satisfies Ax = b.
Answer:
See explaination
Step-by-step explanation:
public class GaussElim{
private static final double eps = 1e-10; % set epsilon value
public static doublic[] fun(double[][] A,double[] b){
int n=b.length; %calculate length of vector b.
for( int j=0;j<n;j++){
int max=j; %find and swap pivot row.
for (int i=j+1;i<n;i++){
if(Math.abs(A[i][j])>Math.abs(A[max][j])){
max=i;
}
}
double[] t1= A[j]; %swap
A[j]=A[max];
A[max]=t1;
double t= b[j]; %swap
b[j]=b[max];
b[max]=t;
if(Math.abs(A[j][j])<=eps){
throw new ArithmeticException("Matrix is singular."); % if matrix A is a singular matrix then throw error.
}
for(int i=j+1;i<n;i++){
double alpha= A[i][j]/A[j][j];
b[i]=b[i]-alpha*b[j];
for(int k=j;k<n;k++){
A[i][k]=A[i][k]-alpha*A[j][k];
}
}
}
double[] x=new double[n]; % back substitution starts here
for(int i=n-1;i>=0;i--){
double sum=0.0;
for(int j=i+1;j<n;j++){
sum=sum+A[i][j]*x[j];
}
x[i]=(b[i]-sum)/A[i][i];
}
return x;
}
public static void main(String[] args){
int n=3;
double[][] A={{1,2,1},{4,2,0},{-1,5,-3}};
double[] b={5,3,21};
double[] x=fun(A,b);
for(int i=0;i<n;i++){
StdOut.println(x[i]);
}
}
}
A pharmaceutical company receives large shipments of aspirin tablets. The acceptance sampling plan is to randomly select and test 14 tablets. The entire shipment is accepted if at most 2 tablets do not meet the required specifications. If a particular shipment of thousands of aspirin tablets actually has a 4.0% rate of defects, what is the probability that this whole shipment will be accepted?
Answer: the probability that this whole shipment will be accepted is 0.673
Step-by-step explanation:
This is a binomial distribution because the probabilities are either that of success or failure
The probability that a particular shipment of thousands of aspirin tablets actually has defects is 4% = 0.04. Then the probability that there would be no defect is 1 - 0.04 = 0.96
Since the shipment is accepted with at most even when there is defect, then the probability of success is 0.04 and that of failure is 0.96
The formula is expressed as
P(x = r) = nCr × p^r × q^(n - r)
Where
x represent the number of successes.
p represents the probability of success.
q = (1 - p) represents the probability of failure.
n represents the number of trials or sample.
From the information given,
p = 0.04
q = 0.96
n = 14
Since entire shipment is accepted if at most 2 tablets do not meet the required specifications, then the probability is
P(x ≤ 2) = P(x = 0) + P(x = 1) + P(x = 2)
P(x = 0) = 14C0 × 0.04^0 × 0.96^(14 - 0) = 0.56
P(x = 1) = 14C1 × 0.04^1 × 0.96^(14 - 1) = 0.024
P(x = 2) = 14C2 × 0.04^2 × 0.96^(14 - 2) = 0.089
P(x ≤ 2) = 0.56 + 0.024 + 0.089 = 0.673
How much money does Bill need for his down payment if his house is $ 450,000? He has to put 10% down.
Bill has a program that gives him 80 percent of that down payment, the rest he has to come up with. How much money does Bill need?
PLEASE HELP ME
Answer:
He would need 45,000 for his down payment. He would only have to come up with 9,000.
Step-by-step explanation:
10% times 450,000 is 45,000.
80% times 45,000 is 36,000. 45,000 minus 3600 is 9,000.
Answer:
$9,000
Step-by-step explanation:
10% of 450000
10/100 × 450000
= 45000
He has 80%, needs to arrange for 100-80 = 20% of the down payment
20/100 × 45000 = 9,000
Evaluate the expression.
|3| + |-1|
A) -2
B) -4
C) 2
D) 4
Answer:
D) 4
Step-by-step explanation:
[tex]|3| + |-1| = 3 + 1 = 4 \\ [/tex]
9. (12 pts) daniel is paying $600 for his auto insurance, and he is wondering if he is overpaying compared to his friends. he sent an email to all his friends in his contact list, and 9 of them replied with their paid amount. suppose the 9 friends who replied are a random sample, and the paid amount for auto insurance has approximately a normal distribution. (1) (2pts) what are the sample and population of the study? (2) (8 pts) use appropriate inference procedure to help daniel find out if he is overpaying compared to his friends. (3) (2pts) based on your conclusion in (2), what type of error is could you commit? explain the error using context words.
Answer:
Step-by-step explanation:
1) The sample and the population of this study is the friends who replied his email which includes in his contact list. then, the number of the replied to his email are 9 friends.
population: the whole friends include in his contact list.
3) Type I error occurs when one incorrectly rejects the null hypothesis
Here there is possibility of type I error
Suppose that A and B each randomly, and independently, choose 3 of 10 objects. Find the expected number of objects (a) chosen by both A and B; (b) not chosen by either A or B; (c) chosen by exactly one of A and B.
Answer:
a) N(A∩B) = 0.9
b) N(A∩B) = 4.9
c) N(A or B) = 4.2
Step-by-step explanation:
Given that A and B each randomly, and independently, choose 3 of 10 objects;
P(A) = P(B) = 3/10 = 0.3
P(A') = P(B') = 1 - 0.3 = 0.7
a) chosen by both;
Probability of being chosen by both;
P(A∩B) = 0.3 × 0.3 = 0.09
Expected Number of objects being chosen by both;
N(A∩B) = P(A∩B) × N(total) = 0.09×10
N(A∩B) = 0.9
b) not chosen by either A or B;
Probability of not being chosen by either A or B;
P(A'∩B') = 0.7 × 0.7 = 0.49
Expected Number of objects being chosen by both;
N(A'∩B') = P(A'∩B') × N(total) = 0.49×10
N(A∩B) = 4.9
c) chosen by exactly one of A and B.
Probability of being chosen by exactly one of A and B
P(A∩B') + P(A'∩B) = 0.3×0.7 + 0.7 × 0.3 = 0.42
Expected Number of objects being chosen by both;
N(A or B) = 0.42 × 10
N(A or B) = 4.2
The expected number of objects chosen by both A and B is 0.9. The expected number of objects not chosen by either A or B is 9.1. The expected number of objects chosen by exactly one of A and B is 4.2.
Explanation:To find the expected number of objects chosen by both A and B, we can use the multiplication rule. Since A and B each independently choose 3 objects from a set of 10, the probability of choosing a specific object is 3/10 for both A and B. Therefore, the expected number of objects chosen by both A and B is (3/10)(3/10)(10) = 0.9.
To find the expected number of objects not chosen by either A or B, we can subtract the expected number of objects chosen by both A and B from the total number of objects. So, the expected number of objects not chosen by either A or B is 10 - 0.9 = 9.1.
To find the expected number of objects chosen by exactly one of A and B, we can use the addition rule. Since A and B each independently choose 3 objects, the probability of choosing a specific object is 3/10 for both A and B. Therefore, the expected number of objects chosen by exactly one of A and B is 2(3/10)(7/10)(10) = 4.2.
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There are two water tanks, Tank #1 fills into Tank #2.
Tank #1 has 200 gallons in it and losing 2 gallons each minute. Tank #2 has 60 gallons in it.
How long will it take for both Tanks to have the same amount of water in them?
Answer:
35 minutes
Step-by-step explanation:
The total amount of water is 200 +60 = 260 gallons. The two tanks will have equal amounts when each has half that, or 130 gallons.
If the volume in tank 2 is increasing at 2 gallons per minute, it will increase by 70 gallons from 60 gallons to 130 gallons in 70/2 = 35 minutes.
We test for a hypothesized difference between two population means: H0: μ1 = μ2. The population standard deviations are unknown but assumed equal. The number of observations in the first sample is 15 and 12 in the second sample. How many degrees of freedom are associated with the critical value?
Answer:
The degrees of freedom associated with the critical value is 25.
Step-by-step explanation:
The number of values in the final calculation of a statistic that are free to vary is referred to as the degrees of freedom. That is, it is the number of independent ways by which a dynamic system can move, without disrupting any constraint imposed on it.
The degrees of freedom for the t-distribution is obtained by substituting the values of n1 and n2 in the degrees of freedom formula.
Degrees of freedom, df = n1+n2−2
= 15+12−2=27−2=25
Therefore, the degrees of freedom associated with the critical value is 25.
A study was conducted in which rats showed compassion by freeing a trapped rat. In the study, all six of the six female rats showed compassion by freeing the trapped rat while 17 of the 24 male rats did so. We found a 95% confidence interval for the difference in proportion of rats showing compassion, using the proportion of female rats minus the proportion of male rats, to be 0.104 to 0.480. In testing whether there is a difference in these two proportions:
What are the null and alternative hypotheses?
Answer:
If the proportion of female rats that show compassion = p₁
And
If the proportion of male rats that show compassion = p₂
And the difference between them is given as
μ₀ = p₁ - p₂
The null hypothesis and alternative hypothesis can be expressed as:
The null hypothesis that there is no significant evidence to conclude that there is a significant difference in the proportion of female rats that show compassion and the proportion of male rats that show compassion.
That is, there is no significant difference in the proportion of female rats that show compassion and the proportion of male rats that show compassion.
H₀: μ₀ = 0
or
H₀: p₁ = p₂
And the alternative hypothesis that there is evidence that the proportion of female rats that show compassion is significantly different from the proportion of male rats that show compassion.
That is, there is a significant difference in the proportion of female rats that show compassion and the proportion of male rats that show compassion.
Hₐ: μ₀ ≠ 0
or
Hₐ: p₁ ≠ p₂
Step-by-step explanation:
For hypothesis testing, the first thing to define is the null and alternative hypothesis.
The null hypothesis plays the devil's advocate and is usually about the absence of significant difference between two proportions being compared. It usually maintains that random chance is responsible for the outcome or results of any experimental study/hypothesis testing. It usually contains the signs =, ≤ and ≥ depending on the directions of the test.
While, the alternative hypothesis usually confirms the the theory being tested by the experimental setup. It proposes that there is indeed a significant difference between two proportions being compared. It usually confirms the theory being tested by the experimental setup.
It usually contains the signs ≠, < and > depending on the directions of the test.
For this question, we want to check whether there is a significant difference in the proportion of female rats that show compassion and the proportion of male rats that show compassion.
If the proportion of female rats that show compassion = p₁
And
If the proportion of male rats that show compassion = p₂
And the difference between them is given as
μ₀ = p₁ - p₂
The null hypothesis and alternative hypothesis can be expressed as:
The null hypothesis that there is no significant evidence to conclude that there is a significant difference in the proportion of female rats that show compassion and the proportion of male rats that show compassion.
That is, there is no significant difference in the proportion of female rats that show compassion and the proportion of male rats that show compassion.
H₀: μ₀ = 0
or
H₀: p₁ = p₂
And the alternative hypothesis that there is evidence that the proportion of female rats that show compassion is significantly different from the proportion of male rats that show compassion.
That is, there is a significant difference in the proportion of female rats that show compassion and the proportion of male rats that show compassion.
Hₐ: μ₀ ≠ 0
or
Hₐ: p₁ ≠ p₂
Hope this Helps!!!
The null hypothesis, denoted as \( H_0 \), states that there is no difference in the proportion of female rats and male rats that show compassion by freeing a trapped rat. In mathematical terms, this can be expressed as:
[tex]\[ H_0: p_f - p_m = 0 \][/tex]
where [tex]\( p_f \)[/tex] is the proportion of female rats showing compassion and [tex]\( p_m \)[/tex] is the proportion of male rats showing compassion.
The alternative hypothesis, denoted as [tex]\( H_1 \) or \( H_a \)[/tex], states that there is a difference in the proportion of female rats and male rats that show compassion. This can be expressed as:
[tex]\[ H_1: p_f - p_m \neq 0 \][/tex]
This is a two-tailed test because the alternative hypothesis does not specify the direction of the difference, only that a difference exists.
Given the confidence interval for the difference in proportions is 0.104 to 0.480, we can see that the interval does not include zero. This suggests that at the 95% confidence level, there is evidence to reject the null hypothesis in favor of the alternative hypothesis, indicating that there is a statistically significant difference between the proportions of female and male rats showing compassion
Chi works cutting lawns. Last week, he worked 34 hours and earned $329.12. What is his hourly wage?
We want to find the number of dollars Chi makes for every hour he cuts lawns. This proportion would be dollars/hour.
329.12 / 34 = 9.68
Chi's hourly wage is $9.68 per hour.
Hope this helps!! :)
A store is having a sale on jelly beans and trail mix. For 6 pounds of jelly beans and 2 pounds of trail mix, the total cost is $22. For 3 pounds of jelly beans and 5 pounds of trail mix, the total cost is $16. Find the cost for each pound of jelly beans and each pound of trail mix.
Answer:
Jelly Bean price per pound = $3.25, Trail Mix price per pound = $1.25
Step-by-step explanation:
Let jb = price per pound of jelly beans
Let tm = price per pound of trail mix
equation 1 -> 6*jb + 2*tm = 22
equation 2 -> 3*jb + 5*tm = 16
simplify equation 1
6*jb + 2tm = 22
2*tm = 22 - 6*jb
divide by 2
tm = 11 - 3*jb
plug this into equation 2
3*jb + 5*tm = 16
3*jb + 5*(11-3*jb) = 16
3*jb + 55 - 15*jb = 16
-12*jb + 55 = 16
-12*jb = 16 - 55
-12*jb = -39
jb = -39/-12
jb = 3.25
then, plug the cost per pound of jelly beans back into the simplified equation 1
tm = 11 - 3*jb
tm = 11 - 3*3.25
tm = 1.25
Please help me I’ve included a picture!
Answer:
257/2 degrees or 128.5 degrees
Step-by-step explanation:
radians to degrees is x radians * 180/π
[tex]\frac{257\pi }{360} * \frac{180}{\pi }= \frac{257}{2}[/tex]
it is 257/2 degrees or 128.5 degrees
Maria works as an electrician and earns $24.68/h. If she worked for 15 hours on one job, how much did she earn? *
Answer:
she would have $370.20
Step-by-step explanation:
24.68*15=370.2
The answer would be 320.2. 24.8 x 15= 320.5
Step-by-step explanation:
A credit card company is about to send out a mailing to test the market for a new credit card. From that sample, they want to estimate the true proportion of people who will sign up for the card nation-wide. A pilot study suggests that about 0.5% of the people receiving the offer will accept it. To be within a tenth of a percentage point (0.001) of the true rate with 95% confidence, how big does the test mailing have to be?
Answer:
[tex]n=\frac{0.005(1-0.005)}{(\frac{0.001}{1.96})^2}=19111.96[/tex]
And rounded up we have that n=19112
Step-by-step explanation:
Previous concepts
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".
Solution to the problem
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by [tex]\alpha=1-0.95=0.05[/tex] and [tex]\alpha/2 =0.025[/tex]. And the critical value would be given by:
[tex]z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96[/tex]
The margin of error for the proportion interval is given by this formula:
[tex] ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}[/tex] (a)
And on this case we have that [tex]ME =\pm 0.001[/tex] and we are interested in order to find the value of n, if we solve n from equation (a) we got:
[tex]n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}[/tex] (b)
And replacing into equation (b) the values from part a we got:
[tex]n=\frac{0.005(1-0.005)}{(\frac{0.001}{1.96})^2}=19111.96[/tex]
And rounded up we have that n=19112
Answer:
We need a mailing list of at least 191112 people.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
For this problem, we have that:
[tex]\pi = 0.005[/tex]
95% confidence level
So [tex]\alpha = 0.05[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.05}{2} = 0.975[/tex], so [tex]Z = 1.96[/tex].
To be within a tenth of a percentage point (0.001) of the true rate with 95% confidence, how big does the test mailing have to be?
They need at least n people
n is found when [tex]M = 0.001[/tex]. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.001 = 1.96\sqrt{\frac{0.005*0.995}{n}}[/tex]
[tex]0.001\sqrt{n} = 1.96\sqrt{0.005*0.995}[/tex]
[tex]\sqrt{n} = \frac{1.96\sqrt{0.005*0.995}}{0.001}[/tex]
[tex](\sqrt{n})^{2} = (\frac{1.96\sqrt{0.005*0.995}}{0.001})^{2}[/tex]
[tex]n = 19111.96[/tex]
We need a mailing list of at least 191112 people.
The population p of a small community on the outskirts of a city grows rapidly over a 20-year period: t05101520p1002004509502000 As an engineer working for a utility company, you must forecast the population 5 years into the future in order to anticipate the demand for power. Employ an exponential model and linear regression to make this prediction. (Round the final answer to the nearest whole number.)
Answer:
The population of the small community, 5 years into the future, after the initial 20-year period = 4268.
Step-by-step explanation:
t | 0 | 5 | 10 | 15 | 20
p | 100 | 200 | 450 | 950 | 2000
The exponential function will look like
p = aeᵏᵗ
where a and k are constants.
Take the natural logarithms of both sides
In p = In aeᵏᵗ
In p = In a + In eᵏᵗ
In p = In a + kt
In p = kt + In a.
We then use linear regression to fit the data of In p against t to obtain k and In a.
t | 0 | 5 | 10 | 15 | 20
p | 100 | 200 | 450 | 950 | 2000
In p | 4.605 | 5.298 | 6.109 | 6.856 | 7.601
In p = kt + In a.
y = mx + b
m = k and b = In a
Performing a linear regression analysis on the now-linear relationship between In p and t and also plotting a graph of the variables.
The regression equation obtained is
y = 0.151x + 4.584
The first attached image shows the equations necessary for the estimation of the linear regression parameters.
The second attached image shows the use of regression calculator and the plot of the function In p versus t.
Comparing
y = 0.151x + 4.584
With
In p = kt + In a.
y = In p
k = 0.151
x = t
In a = 4.584
a = 97.905
The exponential function relating p and t,
p = aeᵏᵗ now becomes
p = 97.905 e⁰•¹⁵¹ᵗ
So, to predict the population 5 years into the future, that is 5 years after the 20 year period.
we need p at t=25 years.
0.151 × 25 = 3.775
p(t=25) = 97.905 e³•⁷⁷⁵ = 4268.41 = 4268.
Hope this Helps!!!
To forecast another 5 years, an exponential growth model can be used. The growth rate 'r' can be estimated using linear regression on the natural log of population figures against time, and this rate can be used to compute the predicted population. However, such a model may not account for influences like resource depletion.
Explanation:To predict the population 5 years into the future, we can use an exponential model and linear regression. The population growth described suggests it follows a sort of exponential process where population counts increase more rapidly as time progresses.
Exponential growth can be modeled using the equation P(t) = P0 * e^(rt), where P(t) is the population at time t, P0 is the initial population, r is the growth rate, and e is the base of natural logarithms. To find 'r', we can plot the natural log of the population against time and apply linear regression. The slope of the regression line estimates the growth rate 'r'. Once we've estimated 'r', we can plug the estimated 'r', the current population P0, and the time (t=25, for 5 years into the future) into the formula to calculate the predicted population.
Though this approach gives an estimate, it's important to note that real-life population dynamics can be influenced by various factors not accounted for in a simple exponential model, such as carrying capacity and resource depletion. Thus, it's more of an optimistic estimate, assuming ideal conditions for continued growth.
Learn more about Exponential growth here:https://brainly.com/question/12490064
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what is 30 pints -1 cup
Answer:
59 cups
Step-by-step explanation:
We need to convert these into the same units first. Remember that 1 pint = 2 cups. This means that 30 pints is equal to 2 * 30 = 60 cups.
Now, we just subtract 1 cup from 60 cups: 60 - 1 = 59 cups.
Thus, the answer is 59 cups.
Hope this helps!
Answer:
29½ pints
Step-by-step explanation:
1 pint = 2 cups
1 cup = ½ pint
30 pints - 1 cup
30 pints - ½ pint
29.5 pints
The data in NutritionStudy include information on nutrition and health habits of a sample of people. One of the variables is Smoke, indicating whether a person smokes or not (yes or no). Use technology to test whether the data provide evidence that the proportion of smokers is different from given that identify themselves as smokers.
Required:
Clearly state the null and alternative hypotheses. Your answer should be an expression.
Answer:
H₀: p = 0.20.
Hₐ: p ≠ 0.20.
Step-by-step explanation:
The question is:
The data in Nutrition Study include information on nutrition and health habits of a sample of 315 people. One of the variables is Smoke, indicating whether a person smokes or not (yes or no). Use technology to test whether the data provide evidence that the proportion of smokers is different from 20% given that 43 identify themselves as smokers. Clearly state the null and alternative hypotheses
In this case we need to test whether the proportion of smokers is different from 20%.
A one-proportion z-test can be used to determine the conclusion for this test.
The hypothesis defined as:
H₀: The proportion of smokers is 20%, i.e. p = 0.20.
Hₐ: The proportion of smokers is different from 20%, i.e. p ≠ 0.20.
The information provided is:
n = 315
X = number of people who identified themselves as smokers = 43
Compute the sample proportion of smokers as follows:
[tex]\hat p=\frac{X}{n}=\frac{43}{315}=0.137[/tex]
Compute the test statistic as follows:
[tex]z=\frac{\hat p-p}{\sqrt{\frac{p(1-p)}{n}}}=\frac{0.137-0.20}{\sqrt{\frac{0.20(1-0.20)}{315}}}=-2.80[/tex]
The test statistic is -2.80.
Compute the p-value as follows:
[tex]p-value=2\times P(Z<-2.80)\\=2\times [1-P(Z<2.80)]\\=2\times [1-0.99744]\\=0.00512[/tex]
*Use a z-table.
The p-value is 0.00512.
The p-value is quite small. So, the null hypothesis will be rejected at any significance level.
Thus, it can be concluded that the proportion of smokers is different from 20%.
The null hypothesis is that the proportion of smokers is 20% and the alternative hypothesis is that the proportion of smokers is not 20%.
What is null hypothesis?The null hypothesis simply means that there's no effect or relationship between the variables while the alternative hypothesis simply states that the prediction of the research has an effect
In this case, the null hypothesis is that the proportion of smokers is 20% and the alternative hypothesis is that the proportion of smokers is not 20%.
Learn more about hypothesis on:
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Expected value is
a. (Probability of state A+Value in state A) (Probability of state B+Value in state B)
b. (Probability of state A*Value in state A)-(Probability of state B*Value in state B)
c. (Probability of state A*Value in state A)+(Probability of state B*Value in state B)
d. (Probability of state A-Value in state A) (Probability of state B-Value in state B)
Answer:
(C). (Probability of state A*Value in state A)+(Probability of state B*Value in state B)
Step-by-step explanation:
The expected value of a probability distribution, E(X) is defined as:
[tex]E(x)=\sum_{i=1} ^{k} x_{i} \cdot P(x_{i})\\$Where x=An Outcome\\P(x)=Probability of that Outcome[/tex]
Given Outcome A and B, the Expected Value therefore is:
Expected Value = (Probability of state A*Value in state A)+(Probability of state B*Value in state B)
Final answer:
The expected value for two mutually exclusive events A and B is calculated as the sum of the products of the probabilities of each event and their corresponding values, thus option c is the correct answer.
Explanation:
The concept of expected value in probability is a fundamental idea in mathematics, particularly in probability theory and statistics. The expected value is calculated as the sum of all possible values, each multiplied by the probability of its occurrence. In the context of two mutually exclusive events A and B, the expected value is computed using the formula:
Expected value = (Probability of state A * Value in state A) + (Probability of state B * Value in state B).
Thus, the correct answer to the student’s question is option c.
3 days after the start of an experiment there were 484 bacteria in a culture. After 5 days there were 1135. Use a system of equations to determine the initial number of bacteria in the culture (c) and the k value for the growth
Answer:
c = 135k = 0.42615Step-by-step explanation:
We assume you want your model to be ...
p = c·e^(kt)
Filling in (t, p) values of (3, 484) and (5, 1135), we have two equations in the two unknowns:
484 = c·e^(3k)
1135 = c·e^(5k)
Taking logs makes these linear equations:
ln(484) = ln(c) +3k
ln(1135) = ln(c) +5k
Subtracting the first equation from the second, we have ...
ln(1135) -ln(484) = 2k
k = ln(1135/484)/2 ≈ 0.42615
Using that value in the first equation, we find ...
ln(484) = ln(c) +3(ln(1135/484)/2)
ln(c) = ln(484) -(3/2)ln(1135/484)
c = e^(ln(484) -(3/2)ln(1135/484)) ≈ 134.8
The initial number in the culture was 135, and the k-value is about 0.42615.
_____
I prefer to start with the model ...
p = 484·(1135/484)^((t-3)/2)
Then the initial value is that obtained when t=0:
c = 484·(1135/484)^(-3/2) = 134.778 ≈ 135
The value of k the log of the base for exponent t. It is ...
ln((1135/484)^(1/2)) = 0.426152
This starting model matches the given numbers exactly. The transformation to c·e^(kt) requires approximations that make it difficult to match the given numbers.
__
For this model, the base of the exponent is the ratio of the two given population values. The exponent is horizontally offset by the number of days for the first count, and scaled by the number of days between counts. The multiplier of the exponential term is the first count. The model can be written directly from the given data, with no computation required.