A technician compares repair costs for two types of microwave ovens (type I and type II). He believes that the repair cost for type I ovens is greater than the repair cost for type II ovens. A sample of 60 type I ovens has a mean repair cost of $⁢85.79, with a standard deviation of $⁢15.13. A sample of 56 type II ovens has a mean repair cost of $78.67, with a standard deviation of $⁢17.84. Conduct a hypothesis test of the technician's claim at the 0.1 level of significance. Let μ1 be the true mean repair cost for type I ovens and μ2 be the true mean repair cost for type II ovens.Step 1 of 4: State the null and alternative hypotheses for the test.Step 2 of 4: Compute the value of the test statistic. Round your answer to two decimal places.Step 3 of 4: Determine the decision rule for rejecting the null hypothesis H0. Round the numerical portion of your answer to three decimal places.Step 4 of 4: Make the decision for the hypothesis test. Reject or Fail to Reject Null Hypothesis

Answer:

B.  0.10 - 0.20 = 0.10.

Step-by-step explanation:

100/1000 = 0.10 of the population were born , and

200/1000 = 0.20 of the population died so it is:

0.10 - 0.20 = 0.10.

Answer: B

Step-by-step explanation:

The total population was initially 1000 individuals. In this population, a total of of 100 new individuals were born over the course of one year. The proportion of new individuals that make up the population is 100/1000 = 0.1

Since they were added, then it is positive and it is a gain for the population.

A total of 200 individuals also died over the course of one year. The proportion that died = 200/1000 = 0.2. This would be negative because it is a loss for the population.

The population growth rate will be gain - loss. This becomes

0.1 - 0.2 = -0.1

Answer:

The function y must be decreasing (or equal to 0) on any interval on which it is defined.

Step-by-step explanation:

The derivative of a function gives us the rate at which that function is changing. In this case, -y^2, yields a negative value for every possible value of y, thus, the rate of change is always negative and the function y is decreasing (or equal to 0) on any interval on which it is defined.

The differential equation y' = -[tex]y^2[/tex] implies that y is either decreasing or constant wherever it is defined, because the derivative y' is non-positive.

By examining the differential equation y' = -[tex]y^2[/tex], we can infer some characteristics about the solutions without solving it. If y is a solution to this equation, then y' represents the derivative of y with respect to x. This derivative tells us about the rate of change of the function y.

Since the right side of the equation is -[tex]y^2[/tex], and a square of a real number is always non-negative, multiplying by -1 makes it non-positive. This implies that the derivative y' is either less than or equal to zero. Therefore, wherever the function y is defined, it must be either decreasing or constant (equal to zero). If y is positive, y will decrease because of the negative sign in front of the square. If y is negative, squaring it results in a positive number, but the negative sign still ensures that the rate of change is non-positive.

Conclusion: the function y is decreasing or remains constant on any interval it is defined; it cannot be increasing.

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Answer:

a) [tex]P(X\leq 12)=0.8586[/tex]

b) [tex]P(X\geq 5)=0.9802[/tex]

c) [tex]P(5\leq X\leq 12)=0.8389[/tex]

Step-by-step explanation:

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Let X the random variable of interest, on this case we now that:

[tex]X \sim Binom(n=20, p=0.48)[/tex]

The probability mass function for the Binomial distribution is given as:

[tex]P(X)=(nCx)(p)^x (1-p)^{n-x}[/tex]

Where (nCx) means combinatory and it's given by this formula:

[tex]nCx=\frac{n!}{(n-x)! x!}[/tex]

We need to check the conditions in order to use the normal approximation.

[tex]np=20*0.48=9.6 \approx 10 \geq 10[/tex]

[tex]n(1-p)=20*(1-0.48)=10.4 \geq 10[/tex]

So we see that we satisfy the conditions and then we can apply the approximation.

If we appply the approximation the new mean and standard deviation are:

[tex]E(X)=np=20*0.48=9.6[/tex]

[tex]\sigma=\sqrt{np(1-p)}=\sqrt{20*0.48(1-0.48)}=2.234[/tex]

Part a

We want this probability:

[tex]P(X\leq 12)[/tex]

We can use the z score given by this formula [tex]Z=\frac{x-\mu}{\sigma}[/tex].

[tex]P(X\leq 12)=P(\frac{X-\mu}{\sigma}\leq \frac{12-9.6}{2.234})=P(Z\leq 1.074)=0.8586[/tex]

Part b

We want this probability:

[tex]P(X\geq 5)[/tex]

We can use again the z score formula and we have:

[tex]P(X\geq 5)=1-P(X<5)=1-P(\frac{X-\mu}{\sigma}< \frac{5-9.6}{2.234})=1-P(Z<- 2.059)=0.9802[/tex]

Part c

We want this probability:

[tex]P(5\leq X\leq 12)=P(\frac{5-9.6}{2.234}\leq \frac{X-\mu}{\sigma}\leq \frac{12-9.6}{2.234})=P(-2.059\leq Z \leq 1.074)[/tex]

[tex]=P(Z<1.074)-P(Z<-2.059)=0.8586-0.0197=0.8389[/tex]

Answer:

Option b) Increase the sample mean

Step-by-step explanation:

Given that a researcher selects a sample from a population with μ = 30 and uses the sample to evaluate the effect of a treatment. After treatment, the sample has a mean of M = 32 and a variance of s2 = 6.

This is a paired test with test statistic

=mean diff/std error

Mean difference would increase if sample mean increases.

This would increase the test statistic

Or otherwise decrease in variance will increase the test statistic

Or Increase in sample size would also increase test statistic

Of all these the II option is definite in increasing the  likelihood of rejecting the null hypothesis because this would definitely increase the chances of rejecting H0.

Others may also have effect but not as much direct as sample mean difference.

Because variance and sample size have influence only upto square root of the difference.

Answer:

Option D is right

Step-by-step explanation:

given that a two sample test for mean of independent samples to be done.

We create hypotheses as:

[tex]H_0: \ bar x = \bar y[/tex] vs alternate suitably right or left or two tailed according to the needs.

The conditions needed for conducting this test would be

I. Both populations are approximately normally distributed

II. Both sample sizes greater than 30

III. Population of differences is approximately normally distributed

i.e. either i, ii or III

Option D is right.

Answer:

209 points

Step-by-step explanation:

Mean points scored (μ) = 182 points  

Standard deviation (σ) = 14 points

The z-score for any given game score 'X' is defined as:  

[tex]z=\frac{X-\mu}{\sigma}[/tex]  

At, the 97th percentile of a normal distribution, the z-score, according to a z-score table, is 1.881.

Therefore, the minimum score, X, needed for a bowler to receive a trophy is:

[tex]1.881=\frac{X-182}{14}\\X=208.334[/tex]

Since only whole point scores are possible, X=209 points.

To find the minimum score at the 97th percentile for bowlers in a league, one must calculate the z-score for the 97th percentile and then apply the formula Score = μ + (z * σ) using the league's mean and standard deviation.

To find the minimum score needed for a bowler to receive a trophy (which is at or above the 97th percentile), we need to use the normal distribution properties. With a mean (μ) of 182 points and a standard deviation (σ) of 14 points, we can find the z-score corresponding to the 97th percentile using a z-table or a calculator with normal distribution functions. Once we have the z-score, we can use the formula:

Score = μ + (z * σ)

to calculate the score that corresponds to the 97th percentile.

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Answer:

Answer is 13.3 ft

Step-by-step explanation:

i explained in the image below

The ideal weight of a 6-foot male (according to the function) is approximately 75.4 kilograms. By manipulating the weight function, we can express height as a function of weight. To verify this function, we substitute it back into the original equation, ensuring our original input value is retrieved.

The question is asking to find the ideal weight of a 6-foot male using the function W(h) = 49 + 2.2(h- 60). The height in inches for a 6-foot male is 72 inches (as 1 foot equals 12 inches). Substituting into the formula we obtain:

W(72) = 49 + 2.2(72 - 60) = 49 + 2.2*12.

Completing the calculation, the ideal weight is about 75.4 kg (rounded to the nearest tenth).

To express height h as a function of weight W, we need to rearrange the function W(h). Subtracting 49 from both sides yields 2.2(h - 60) = W - 49. Then divide both sides by 2.2 to isolate h, resulting in h = (W - 49) / 2.2 + 60.

Verification that W(h(W)) = W and h(W(h)) = h will require substituting the functions back into each other, and determining that the original input is returned.

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Answer:

H₀: σ² ≥ 17956

H₁: σ² < 17956

Step-by-step explanation:

Hello!

You are asked to test if the population standard deviation of a certain population. Now keep in mind that wherever you want to make a hypothesis test for a population parameter, you have to have a known distribution that includes this parameter. Since the population standard deviation is no parameter of any distribution, what you have to do is test the population variance. Any decision you make about the population variance can be extrapolated to the population standard deviation.

To make a hypothesis test for the population variance, you need a variable with normal distribution and the statistic to use is a Chi-square statistic.

The hypothesis is that the population standard deviation is less than 134, symbolically: σ < 134

Translated in terms of the population variance: σ² < 17956

H₀: σ² ≥ 17956

H₁: σ² < 17956

α: 0.05

χ²=  (n-1)S²  ~χ²[tex]_{n-1}[/tex]

σ²

χ²=  (27-1)(126)²  = 22.988

17956

The test is one tailed (left)

χ²[tex]_{n-1;α}[/tex] =χ²[tex]_{26;0.05}[/tex] = 15.379

If the calculated Chi-square value is ≤ than the critical value, you reject the null hypothesis.

If the calculated Chi-square value is > than the critical value, you don't reject the null hypothesis.

Since the value is greater than the critical value, you do not reject the null hypothesis. So at a 5% level, there is not enough evidence to reject the null hypothesis, this means the population variance is at least 17956. On the same level, you can conclude that the population standard deviation is at least 134.

I've made the test so that you have an example of how to do it.

I hope it helps!

Answer:

5/8,-5√2,{(2x+3)(x-5)}

Step-by-step explanation:

1) 5x-10/8x-16

=5(x-2)/8(x-2)

=5/8

2) √32-3√18

=4√2-3√18

=4√2-9√2

=(4-9)√2

= -5√2

4) 2x^2-7x-15

=2x^2+3x-10x-15

=(2x+3),(x-5)

Answer: 95% confidence interval would be (0.344,0.456).

Step-by-step explanation:

Since we have given that

n = 295

x = 118

so, [tex]\hat{p}=\dfrac{x}{n}=\dfrac{118}{295}=0.4[/tex]

At 95% confidence, z = 1.96

So, margin of error would be

[tex]z\times \sqrt{\dfrac{p(1-p)}{n}}\\\\=1.96\times \sqrt{\dfrac{0.4\times 0.6}{295}}\\\\=0.056[/tex]

so, 95% confidence interval would be

[tex]\hat{p}\pm \text{margin of error}\\\\=0.4\pm 0.056\\\\=(0.4-0.056,0.4+0.056)\\\\ =(0.344,0.456)[/tex]

Hence, 95% confidence interval would be (0.344,0.456).

Answer:

Step-by-step explanation:

P-value for the airline's claim that the no-show rate for passengers booked on its flights is less than 6% is 0.2061. Hence, option (B) is correct.

Given that, an airline claims that the no-show rate for passengers booked on its flights is less than 6%.

From this claim, it is clear that:

Null hypothesis :  Proportion of no-show rate for passengers booked on its flights, P = 6%. i.e. H₀: P = 0.06

Alternative hypothesis: Proportion of no-show rate for passengers booked on its flights P < 6%, i.e. P < 0.06.

Out of 380 randomly selected reservations, 19 were no-shows

Sample proportion, [tex]\hat{p} = \frac{19}{380}[/tex]  = 0.05

Then, the standard error for the sample size of 380 is:

[tex]\text{S.E.} = \sqrt{{\frac{p(1-p)}{n}[/tex]

[tex]\text{S.E.} = \sqrt{{\frac{0.06(1-0.06)}{380}[/tex]

[tex]\text{S.E.} = 0.012[/tex]

Now calculating the test statistic

[tex]z = \frac{( \hat{p} - P)}{S.E}[/tex]

[tex]z = \frac{(0.05 - 0.06)}{0.012 }[/tex]

z = -0.833

p value for z = -0.083 is 0.2061 (From the normal table).

Hence, the p-value for a test of the airline's claim is 0.2061. Option (B) is correct.

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Final answer:

To find the P-value for the hypothesis test, calculate the sample proportion and standard error, then use the standard normal distribution to calculate the z-score and find the corresponding P-value.

Explanation:

To find the P-value for the hypothesis test, we need to use the given data and perform calculations.

First, we need to calculate the sample proportion, which is the number of no-shows divided by the total number of reservations: 19/380 = 0.05.

Next, we calculate the standard error of the sample proportion using the formula: √((p' * (1 - p')) / n), where p' is the sample proportion and n is the sample size. In this case, the standard error is √((0.05 * (1 - 0.05)) / 380) = 0.014.

Finally, we use the standard normal distribution to calculate the z-score and find the corresponding P-value. In this case, the observed proportion is less than the claimed proportion, so we use a one-tailed test and calculate the z-score as (observed proportion - claimed proportion) / standard error = (0.05 - 0.06) / 0.014 = -0.714. Looking up the P-value for a z-score of -0.714, we find that it is approximately 0.4714.

Therefore, the P-value for the test of the airline's claim is approximately 0.4714.

Answer:

                          Hamburger       Chicken

Adults                    65                        60         125

children                 55                        20          75

                             120                        80         200

a)What is the probability that a randomly selected individual is an adult?

Total no. of adults = 125

Total no. of people  200

The probability that a randomly selected individual is an adult = [tex]\frac{125}{200}=0.625[/tex]

b) What is the probability that a randomly selected individual is a child and prefers chicken?

No. of child prefers chicken = 20

The probability that a randomly selected individual is a child and prefers chicken= [tex]\frac{20}{200}=0.1[/tex]

c)Given the person is a child, what is the probability that this child prefers a hamburger?

No. of children prefer hamburger = 55

No. of child = 75

The probability that this child prefers a hamburger= [tex]\frac{35}{75}=0.46[/tex]

d) Assume we know that a person has ordered chicken, what is the probability that this individual is an adult?

No. of adults prefer chicken = 60

No. of total people like chicken = 80

A person has ordered chicken, the probability that this individual is an adult= [tex]\frac{60}{80}=0.75[/tex]

Final answer:

The probability that a randomly selected individual is an adult is 0.625. The probability that a randomly selected individual is a child and prefers chicken is 0.10. Given a child, the probability of preferring a hamburger is approximately 0.733, and given that a person ordered chicken, the probability that they are an adult is 0.75.

Explanation:

Let's address the questions based on the contingency table provided:

Probability Calculations

a) The probability that a randomly selected individual is an adult can be calculated as follows:

The number of adults: 125

The total number of respondents: 200

Probability(Adult) = Number of Adults / Total Number of Respondents = 125 / 200 = 0.625

b) The probability that a randomly selected individual is a child and prefers chicken:

The number of children who prefer chicken: 20

The total number of respondents: 200

Probability(Child and Chicken) = Number of Children who prefer Chicken / Total Number of Respondents = 20 / 200 = 0.10

c) If the person is a child, the probability that this child prefers a hamburger:

The number of children who prefer hamburger: 55

The total number of children: 75

Probability(Hamburger | Child) = Number of Children who prefer Hamburger / Total Number of Children = 55 / 75 ≈ 0.733

d) Given that a person has ordered chicken, the probability that this individual is an adult:

The number of adults who prefer chicken: 60

The total number of chicken preferences: 80

Probability(Adult | Chicken) = Number of Adults who prefer Chicken / Total Number of Chicken Preferences = 60 / 80 = 0.75

Answer:

sin(t)j - cos(t)i

Step-by-step explanation:

Let's start with A:

Position vector = cos(t)i

Velocity vector = -sin(t)i (differentiating the position vector)

acceleration vector = -cos(t)i   (differentiating the velocity vector)

Then we go to B:

Position vector = sin(t)j

Velocity vector = cos(t)j

acceleration vector = -sin(t)j

Relative acceleration = -cos(t)i - (-sin(t)j) = sin(t)j - cos(t)i

Answer:

10 ft x 10 ft

Area = 100 ft^2

Step-by-step explanation:

Let 'S' be the length of the southern boundary fence and 'W' the length of the eastern and western sides of the fence.

The total area is given by:

[tex]A=S*W[/tex]

The cost function is given by:

[tex]\$ 120 = \$3*2W+\$6*S\\20 = W+S\\W = 20-S[/tex]

Replacing that relationship into the Area function and finding its derivate, we can find the value of 'S' for which the area is maximized when the derivate equals zero:

[tex]A=S*(20-S)\\A=20S-S^2\\\frac{dA}{dS} = \frac{d(20S-S^2)}{dS}\\0= 20-2S\\S=10[/tex]

If S=10 then W =20 -10 = 10

Therefore, the largest area enclosed by the fence is:

[tex]A=S*W\\A=10*10 = 100\ ft^2[/tex]

Answer:

the probability is 38,46%

Step-by-step explanation:

If all decks are put together and shuffled , then card is picked at random regardless of the number, then the probability that the card is red is

probability = number of red cards / total number of cards = 5/(5+2+6) = 5/13=0.3846= 38,46%

Answer:

We conclude that the plant should shut down.

Step-by-step explanation:

We are given the following in the question:

Population mean, μ = 60

Sample mean, [tex]\bar{x}[/tex] = 61.498

Sample size, n = 100

Alpha, α = 0.05

Population standard deviation, σ = 6

a) First, we design the null and the alternate hypothesis  such that the power plant will be shut down when the null hypothesis is rejected.

[tex]H_{0}: \mu \leq 60\\H_A: \mu > 60[/tex]

We use One-tailed(right) z test to perform this hypothesis.

b) 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{61.498 - 60}{\frac{6}{\sqrt{100}} } = 2.49[/tex]

Now, [tex]z_{critical} \text{ at 0.05 level of significance } = 1.64[/tex]

Since,  

[tex]z_{stat} > z_{critical}[/tex]

We reject the null hypothesis and accept the alternate hypothesis. Thus, the temperature of waste water discharged is greater than 60°F. We conclude that the power plant will shut down.

Calculating the p-value from the z-table:

P-value = 0.0063

Since,

P-value < Significance level

We reject the null hypothesis and accept the alternate hypothesis. Thus, the temperature of waste water discharged is greater than 60°F. We conclude that the power plant will shut down.

Answer:

add the decimals thats all

Step-by-step explanation:

Answer:

On this case the 0.09 value is not included on the interval so we can say that the statement on the television news broadcast reports, is a value away from the real proportion at least at 95% of confidence.

Step-by-step explanation:

1) Notation and definitions

[tex]X=34[/tex] number of people living at USA with a particular disease.

[tex]n=527[/tex] random sample taken

[tex]\hat p=\frac{34}{527}=0.0645[/tex] estimated proportion of people living at USA with a particular disease

[tex]p[/tex] true population proportion of people living at USA with a particular disease.

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".  

The population proportion have the following distribution

[tex]p \sim N(p,\sqrt{\frac{\hat p(1-\hat p)}{n}})[/tex]

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 confidence interval for the mean is given by the following formula:  

[tex]\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}[/tex]

If we replace the values obtained we got:

[tex]0.0645 - 1.96\sqrt{\frac{0.0645(1-0.0645)}{527}}=0.0435[/tex]

[tex]0.0645 + 1.96\sqrt{\frac{0.0645(1-0.0645)}{527}}=0.0855[/tex]

The 95% confidence interval would be given by (0.0435;0.0855)

On this case the 0.09 value is not included on the interval so we can say that the statement on the television news broadcast reports, is a value away from the real mean at least at 95% of confidence.

Answer:

0.6284,0.4335,0.1953.0.9786

Step-by-step explanation:

Given that X the number of material anomalies occurring in a particular region of an aircraft gas-turbine disk is following a poisson distribution with parameter 4

a) [tex]P(X\leq 4)=0.6284\\P(X<4)=0.4335[/tex]

b) [tex]P(4\leq x<5)\\=P(4)=0.1953\\[/tex]

c) P([tex]5\leq x)[/tex]=0.8046

d) the probability that the number of anomalies does not exceed the mean value by more than one standard deviation

=[tex]P(0\leq X\leq 8)\\=F(8)-F(0)\\=0.9786[/tex]

Parameterize the line segments by

[tex]\vec r(t)=(1-t)\langle1,1,1\rangle+t\langle2,2,2\rangle=\langle1+t,1+t,1+t\rangle[/tex]

and

[tex]\vec s(t)=(1-t)\langle2,2,2\rangle+t\langle3,6,8\rangle=\langle2+t,2+4t,2+6t\rangle[/tex]

both with [tex]0\le t\le1[/tex]. Then

[tex]\vec r'(t)=\langle1,1,1\rangle[/tex]

[tex]\vec s'(t)=\langle1,4,6\rangle[/tex]

so that the work done by [tex]\vec F(x,y,z)=\langle\sin(x+y),xy,x^2z\rangle[/tex] over the respective line segments is given by

[tex]\displaystyle\int_{C_1}\vec F\cdot\mathrm d\vec r=\int_0^1\langle\sin(2+2t),(1+t)^2,(1+t)^3\rangle\cdot\langle1,1,1\rangle\,\mathrm dt[/tex]

[tex]=\displaystyle\int_0^1\sin(2+2t)+(1+t)^2+(1+t)^3\,\mathrm dt=\boxed{\frac{73+6\cos2-6\cos4}{12}}[/tex]

and

[tex]\displaystyle\int_{C_2}\vec F\cdot\mathrm d\vec s=\int_0^1\langle\sin(4+5t),(2+t)(2+4t),(2+t)^2(2+6t)\rangle\cdot\langle1,4,6\rangle\,\mathrm dt[/tex]

[tex]=\displaystyle\int_0^1\sin(4+5t)+4(2+t)(2+4t)+6(2+t)^2(2+6t)\,\mathrm dt=\boxed{\frac{3695+3\cos4-3\cos9}{15}}[/tex]

(both measured in Newton-meters)

To compute the work done by the force in this scenario, we need to apply the principle of line integrals of force with respect to displacement, calculating work for each segment of the trajectory separately and then adding these results.

Computing work done by the given force while moving an object generally involves utilizing the line integral of the force with respect to displacement. The principle is simplistically shown in the equation W = F⋅d = Fd cos θ, where W represents work, F denotes force, and d symbolizes displacement, with '⋅' denoting the dot product, and cos θ representing the cosine of the angle between the force and displacement vectors. F can break down into its components, such as Fx, Fy, Fz, and similarly, d can be broken down to dx, dy, dz. Using these, we can express work for three dimensions as dW = Fxdx + Fydy + Fzdz which extends the notion of work done to three-dimensional space. This concept is categorically illustrated while calculating the infinitesimal work done by a variable force.

The trajectory (path) for this problem can be divided into two line segments, one from (1, 1, 1) to (2, 2, 2) and the other from (2, 2, 2) to (3, 6, 8). The work for each segment can be calculated independently, based on the variable force function and the displacement during each segment, after which the two results can be added up to determine the total work done.

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Answer: c) [tex]H_0:\mu= 1.5\\\\H_a:\mu \neq1.5[/tex]

Step-by-step explanation:

Given: Nestor Milk Powder is sold in packets with an advertised mean weight of 1.5 kgs.  

i.e. [tex]\mu= 1.5[/tex]  

A consumer group wishes to check the accuracy of the advertised mean and takes a sample of 52 packets finding an average weight of 1.49 kgs.

So 1.49 is sample mean but hypothesis is the statement about the parameter which is [tex]\mu[/tex].

i.e. he wanted to check whether [tex]\mu= 1.5[/tex] or [tex]\mu \neq1.5[/tex]

Since null hypothesis[tex](H_0)[/tex] contains equality and alternative hypothesis[tex](H_a)[/tex] is against it.

Therefore, the set of hypotheses that should be used to test the accuracy of advertised weight would be :

[tex]H_0:\mu= 1.5\\\\H_a:\mu \neq1.5[/tex]

Hence, the correct answer is option c) oH: μ= 1.5; 1H: μ≠1.5

Answer:

[tex]P(X=k) = \displaystyle\frac{(2.5)^ke^{-2.5}}{k!}[/tex]

Step-by-step explanation:

This is a typical example where the Poisson distribution is a good choice to model the situation.

In this case we have an interval of time of 50 milliseconds as average time for the server to address one request and 50 requests per second.  

By cross-multiplying we determine the expected value of requests every 50 milliseconds.  

We know 1 second = 1,000 milliseconds

50 requests __________ 1000 milliseconds

 x requests __________ 50 milliseconds

50/x = 1000/50 ===> x = 2.5  

and the expected value is 2.5 requests per interval of 50 milliseconds.

According to the Poisson distribution, the probability of k events in 50 milliseconds equals

[tex]\bf P(X=k) = \displaystyle\frac{(2.5)^ke^{-2.5}}{k!}[/tex]

Answer:

21/64

Step-by-step explanation:

First, we need to note that the function f(x) = x² is increasing on (0, +∞), and it is decreasing on (-∞,0)

The first interval generated by the partition is [-1, -1/2], since f is decreasing for negative values, we have that f takes its minimum values at the right extreme of the interval, hence -1/2.

The second interval is [-1/2, 1/2]. Here f takes its minimum value at 0, because f(0) = 0, and f is positive otherwise.

Since f is increasing for positive values of x, then, on the remaining 2 intervals, f takes its minimum value at their respective left extremes, in other words, 1/2 and 3/4 respectively.

We obtain the lower Riemman sum by multiplying this values evaluated in f by the lenght of their respective intervals and summing the results, thus

LP(f) = f(-1/2) * ((-1/2) - (-1)) + f(0) * (1/2 - (-1/2)) + f(1/2)* (3/4 - 1/2) + f(3/4) * (1- 3/4)

= 1/4 * 1/2 + 0 * 1 + 1/4 * 1/4 + 9/16 * 1/4 = 1/8 + 0 + 1/16 + 9/64 = 21/64

As a result, the lower Riemann sum on the partition P is 21/64

Final answer:

To compute the lower Riemann sum for the given function f(x) = x² over the interval x ∈ [-1,1] with respect to the partition P = [-1, -1/2, 1/2, 3/4 ,1], we need to find the height of each subinterval and multiply it by the width of the subinterval. The lower Riemann sum is 5/8.

Explanation:

To compute the lower Riemann sum for the given function f(x) = x² over the interval x ∈ [-1,1] with respect to the partition P = [-1, -1/2, 1/2, 3/4 ,1], we need to find the height of each subinterval and multiply it by the width of the subinterval.

First, let's calculate the width of each subinterval:

width of subinterval 1: (-1) - (-1) = 0

width of subinterval 2: (-1/2) - (-1) = 1/2

width of subinterval 3: (1/2) - (-1/2) = 1

width of subinterval 4: (3/4) - (1/2) = 1/4

width of subinterval 5: (1) - (3/4) = 1/4

Next, let's calculate the height of each subinterval by substituting the left endpoint of each subinterval into the function:f((-1/2))^2 = 1/4, f(1/2)² = 1/4, f(3/4)² = 9/16, f(1)² = 1

Finally, we compute the lower Riemann sum by multiplying the height by the width for each subinterval and summing them up:

(0 * 0) + (1/2 * 1/4) + (1 * 9/16) + (1/4 * 1) = 5/8.

Answer:

The answer is a 100,000-choose-99 (a combination.)

[tex]P(100000, 99) = \displaystyle \left( \begin{array}{c}100000\cr 99\end{array}\right)[/tex].

Step-by-step explanation:

A combination [tex]C(n, r)[/tex] or equivalently [tex]\displaystyle \left(\begin{array}{c}n \cr r\end{array}\right)[/tex] gives the number of ways to choose [tex]r[/tex] out of [tex]n[/tex] elements.

A permutation [tex]P(n, r)[/tex] also gives the number of ways to choose [tex]r[/tex] out of [tex]n[/tex] elements. On top of that, it accounts for the order of the elements. Two elements in different order counts twice in a permutation, but only once in a combination.

The question emphasize that the council members are "co-equal." That implies that the order of the members don't really matter. Hence a combination with [tex]n = 100000[/tex] and [tex]r = 99[/tex] would be a more suitable choice.

Answer: [tex]60,540< \mu<70,060[/tex]

Step-by-step explanation:

The confidence interval for population mean is given by :-

[tex]\overline{x}-z^*\dfrac{\sigma}{\sqrt{n}}< \mu<\overline{x}+z^*\dfrac{\sigma}{\sqrt{n}}[/tex]

, where [tex]\sigma[/tex] = Population standard deviation.

n= sample size

[tex]\overline{x}[/tex] = Sample mean

z* = Critical z-value .

Given :  [tex]\sigma=\$17,000[/tex]

n= 49

[tex]\overline{x}= \$65,300[/tex]

Two-tailed critical value for 95% confidence interval = [tex]z^*=1.960[/tex]

Then, the 95% confidence interval would be :-

[tex]65,300-(1.96)\dfrac{17000}{\sqrt{49}}< \mu<65,300+(1.96)\dfrac{17000}{\sqrt{49}}[/tex]

[tex]=65,300-(1.96)\dfrac{17000}{7}< \mu<65,300+(1.96)\dfrac{17000}{7}[/tex]

[tex]=65,300-4760< \mu<65,300+4760[/tex]

[tex]=60,540< \mu<70,060[/tex]

Hence, the 95​% confidence interval for estimating the population mean [tex](\mu)[/tex] :

[tex]60,540< \mu<70,060[/tex]

Answer:

a) t =  2.7638

b) t = - 2.6245

c) t = 3.1058      on the right side    and

   t  = -3.1058    on the left

Step-by-step explanation:

a)Determine critical value for a right-tail test  for α = 0.01 level of significance and 10 degrees of fredom

From t-student table we find:

gl  =  10   and α = 0.01       ⇒  t =  2.7638

b)Determine   critical value for a left-tail test  for α = 0.01 level of significance  and sample size n = 15

From t-student table we find:

gl  =  14   and α = 0.01           gl  =  n - 1      gl  = 15 - 1    gl = 14

t = - 2.6245

c) Determine critical value for a two tails-test  for α = 0.01 level of  significance the  α/2   =   0.005  and sample size  n = 12

Then

gl  =  11   and α = 0.005

t = 3.1058      on the right side of the curve and by symmetry

t = - 3.1058  

From t-student table we find:

Answer:

a) Nina decreases the confidence level to 90%?  (Decrease)

b) Nina decreases the sample size to 34 locations? (Increase)

c) Nina increases the sample size to 70 locations?   (Decrease)

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".

[tex]\bar X[/tex] represent the sample mean for the sample  

[tex]\mu[/tex] population mean (variable of interest)

s represent the sample standard deviation

n=48 represent the original sample size  

Confidence =95% or 0.95

ME=4.28 represent the margin of error.

The confidence interval for the mean is given by the following formula:

[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex]   (1)

In order to calculate the mean and the sample deviation we can use the following formulas:  

[tex]\bar X= \sum_{i=1}^n \frac{x_i}{n}[/tex] (2)  

[tex]s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}[/tex] (3)  

And the margin of error is given by the following expression:

[tex]ME= t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex]   (4)

Based on the formula (4) we can answer all the questions involved:

a) Nina decreases the confidence level to 90%?

On this case the value for [tex]t_{\alpha/2}[/tex] will also decrease so the margin of error would decrease.

b) Nina decreases the sample size to 34 locations?

If we analyze the original sample size of 48 we see that if we reduce the value of n to 34, the margin of error would increase, because n is on the denominator of the margin of error.

c) Nina increases the sample size to 70 locations?

If we analyze the original sample size of 48 we see that if we increase the value of n to 70, the margin of error would decrease, because n is on the denominator of the margin of error.

Answer:

53¢

Step-by-step explanation:

First, I'll put these in order.

20¢;30¢; 30¢;75¢;40¢;40¢;40¢;40¢;50¢;55¢55¢65¢;65¢; $1.50;  

Then, I'll combine like terms.

30+30=60

40+40+40+40(or 40 x 4)=160

55+55=110

65+65=130

60+160+110+130+20+75+50+$1.50=$7.55/14=53¢

PLZ correct me if i'm wrong :-D

Answer:

B

Step-by-step explanation: