A researcher wants to know whether athletic men are more flexible than non-athletic men. For this experiment, a man who exercised vigorously at least four times per week was considered "athletic." Flexibility is measured in inches on a sit & reach box. Test the researcher's claim using the Following summary statistics: $\begin{array}{|l|l|} \hline \text { Athletic men } & \text { Non-athletic men } \\ \hline n=50 & n=40 \\ \hline \bar{x}=4.3 \text { inches } & \bar{x}=3.2 \\ \hline s=2.1 \text { inches } & s=1.0 \text { inches } \\ \hline \end{array}$ Assume that all conditions for testing have been met. Report the test statistic and p-value. At the $5 \%$ significance level, state your decision regarding the null hypothesis and your conclusion about the original claim. Round all values to the nearest thousandth.

A) $\mathrm { t } = - 3.270 ; \mathrm { p } = 0.002$; Reject the null hypothesis; there is strong evidence to suggest that athletic men are more flexible than non-athletic men. B) $t = 3.270 ; \mathrm { p } = 0.001$; Fail to reject the null hypothesis; there is not strong evidence to suggest that athletic men are more flexible than non-athletic men. C) $t = 3.270 ; \mathrm { p } = 0.001$; Reject the null hypothesis; there is strong evidence to suggest that athletic men are more flexible than non-athletic men. D) $t = - 3.270 ; p = 0.002$; Reject the null hypothesis; there is not strong evidence to suggest that athletic men are more flexible than non-athletic men. A) $\mathrm { t } = - 3.270 ; \mathrm { p } = 0.002$; Reject the null hypothesis; there is strong evidence to suggest that athletic men are more flexible than non-athletic men. B) $t = 3.270 ; \mathrm { p } = 0.001$; Fail to reject the null hypothesis; there is not strong evidence to suggest that athletic men are more flexible than non-athletic men. C) $t = 3.270 ; \mathrm { p } = 0.001$; Reject the null hypothesis; there is strong evidence to suggest that athletic men are more flexible than non-athletic men. D) $t = - 3.270 ; p = 0.002$; Reject the null hypothesis; there is not strong evidence to suggest that athletic men are more flexible than non-athletic men.

A researcher wants to know if mood is affected by music. She conducts a test on a sample of 4 randomly selected adults and measures mood rating before and after being exposed to classic rock Music. Test the hypothesis that mood rating decreased after being exposed to classic rock music. Following are the mood ratings for the four participants: $\begin{array}{|l|l|l|}\hline & \begin{array}{c} \text { Before } \\ \text { exposure } \end{array} & \begin{array}{c} \text { After } \\ \text { exposure } \end{array} \\ \hline \text { Participant \#1 } & 5.1 & 5.2 \\ \hline \text { Participant \#2 } & 4.3 & 4.0 \\ \hline \text { Participant \#3 } & 2.5 & 2.5 \\ \hline \text { Participant \#4 } & 4.9 & 4.0 \\ \hline \end{array}$ Assume that all conditions for testing have been met. Report the null and alternative hypothesis and p-value. At the $5 \%$ significance level, state your decision regarding the null hypothesis and your conclusion about the original claim. Round all values to the nearest thousandth.

A) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.154$; Fail to reject the null hypothesis; there is not strong evidence to suggest that exposure to classic rock music decreased mood rating. B) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.015$; Fail to reject the null hypothesis; there is not strong evidence to suggest that exposure to classic rock music decreased mood rating. C) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.154$; Reject the null hypothesis; there is strong evidence o suggest that exposure to classic rock music decreased mood rating. D) $\mathrm { H } _ { 0 }$ : $\mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } \neq 0 ; \mathrm { p } = 0.309$; Reject the null hypothesis; there is strong evidence to suggest that exposure to classic rock music decreased mood rating. A) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.154$; Fail to reject the null hypothesis; there is not strong evidence to suggest that exposure to classic rock music decreased mood rating. B) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.015$; Fail to reject the null hypothesis; there is not strong evidence to suggest that exposure to classic rock music decreased mood rating. C) $\mathrm { H } _ { 0 } : \mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } > 0 ; \mathrm { p } = 0.154$; Reject the null hypothesis; there is strong evidence o suggest that exposure to classic rock music decreased mood rating. D) $\mathrm { H } _ { 0 }$ : $\mu _ { \text {difference } } = 0 , \mathrm { H } _ { \mathrm { a } } : \mu _ { \text {difference } } \neq 0 ; \mathrm { p } = 0.309$; Reject the null hypothesis; there is strong evidence to suggest that exposure to classic rock music decreased mood rating.

Exam 9: Inferring Population Means

Use the following information to answer the question. According to the website ww.costofwedding.com, the average cost of flowers for a wedding is $698. Recently, in a random sample of 40 weddings in the U.S. it was found that the average cost of the flowers was $734, with a standard deviation of $102. On the basis of this, a 95% confidence interval for the mean cost of flowers for a wedding is $701 to $767. -For this description, which of the following does not describe a condition for a valid confidence interval?

(Multiple Choice)

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Question 21

Calculate the standard error for the mean finish time of 30 randomly selected male participants. Show all your work and round to the nearest thousandth.

(Essay)

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Question 22

The quality engineer at a paint manufacturer conducted a hypothesis test to test the claimthat the mean volume of paint cans had changed after an adjustment in the manufacturingprocess. Mean volume in paint cans before the adjustment was 1.02 gallons. Assume thatall conditions for testing have been met. She used technology to complete the hypothesistest. Following is the null and alternative hypothesis and the output from her graphingcalculator. $\mathrm { H } _ { 0 } : \mu = 1.02$ gallons $\mathrm { H } _ { \mathrm { a } } : \mu \neq 1.02$ gallons T-Test \mu1.02 t=-5.89255651 p=3.4248373E-7 =.97 Sx=.06 n=50 Write a statement explaining what her decision regarding the null hypothesis should beand a statement summarizing her conclusion regarding the claim that average volume ofpaint cans had changed. Has the adjustment in the manufacturing process changed theaverage volume of paint cans?

(Essay)

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Question 23

Choose the statement that describes a situation where a confidence interval and a hypothesis test will yield the same results.

(Multiple Choice)

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Question 24

Suppose that the average pop song length in America is 4 minutes with a standard deviation of 1.25 minutes. It is known that song length is not normally distributed. Suppose a sample of 25 songs is Taken from the population. What is the approximate probability that the average song length will Be less than 3.5 minutes? Round to the nearest thousandth.

(Multiple Choice)

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Question 25

Verify that the conditions for a valid confidence interval are met.

(Essay)

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Question 26

A researcher wants to know whether athletic men are more flexible than non-athletic men. For this experiment, a man who exercised vigorously at least four times per week was considered "athletic." Flexibility is measured in inches on a sit & reach box. Test the researcher's claim using the Following summary statistics: Athletic men Non-athletic men n=50 n=40 =4.3 inches =3.2 s=2.1 inches s=1.0 inches Assume that all conditions for testing have been met. Report the test statistic and p-value. At the $5 \%$ significance level, state your decision regarding the null hypothesis and your conclusion about the original claim. Round all values to the nearest thousandth.

(Multiple Choice)

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Question 27

Use the following information to answer the question. According to the website ww.costofwedding.com, the average cost of flowers for a wedding is $698. Recently, in a random sample of 40 weddings in the U.S. it was found that the average cost of the flowers was $734, with a standard deviation of $102. On the basis of this, a 95% confidence interval for the mean cost of flowers for a wedding is $701 to $767. -Choose the statement that is the best interpretation of the confidence interval.

(Multiple Choice)

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Question 28

Use the following information to answer the question. According to the website ww.costofwedding.com, the average cost of flowers for a wedding is $698. Recently, in a random sample of 40 weddings in the U.S. it was found that the average cost of the flowers was $734, with a standard deviation of $102. On the basis of this, a 95% confidence interval for the mean cost of flowers for a wedding is $701 to $767. -Does the confidence interval provide evidence that the mean cost of flowers for a wedding has increased?

(Multiple Choice)

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Question 29

Use the following information to answer the question. According to the website ww.costofwedding.com, the average cost of flowers for a wedding is $698. Recently, in a random sample of 40 weddings in the U.S. it was found that the average cost of the flowers was $734, with a standard deviation of $102. On the basis of this, a 95% confidence interval for the mean cost of flowers for a wedding is $701 to $767. -Suppose that the average song length in America is 4 minutes with a standard deviation of 1.25 minutes. It is known that song length is not normally distributed. Find the probability that a single Randomly selected song from the population will be longer than 4.25 minutes. Round to the nearest Thousandth.

(Multiple Choice)

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Question 30

Suppose a consumer product researcher wanted to find out whether a highlighter lasted less than the manufacturer's claim that their highlighters could write continuously for 14 hours. The Researcher tested 40 highlighters and recorded the number of continuous hours each highlighter Wrote before drying up. Test the hypothesis that the highlighters wrote for less than 14 continuous Hours. Following are the summary statistics: $\bar { x } = 13.6 \text { hours, } s = 1.3 \text { hours }$ Report the test statistic, p-value, your decision regarding the null hypothesis, and your conclusion About the original claim. Round all values to the nearest thousandth.

(Multiple Choice)

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Question 31

Use the following information to answer the question. A sprint duathlon consists of a 5 km run, a 20 km bike ride, followed by another 5 km run. The mean finish time of all participants in a recent large duathlon was 1.67 hours with a standard deviation of 0.25 hours. Suppose a random sample of 30 participants was taken and the mean finishing time was found to be 1.59 hours with a standard deviation of 0.30 hours. -A researcher wants to know whether athletic women are more flexible than non-athletic women. For this experiment, a woman who exercised vigorously at least four times per week was Considered "athletic." Flexibility is measured in inches on a sit & reach box. Test the researcher's Claim using the following summary statistics: Athletic women Non-athletic women n=50 n=30 =5.0 inches =4.6 inches s=1.4 inches s=0.8 inches Assume that all conditions for testing have been met. Report the test statistic and p-value. At the 1% significance level, state your decision regarding the null hypothesis and your conclusion about The original claim. Round all values to the nearest thousandth.

(Multiple Choice)

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Question 32

Suppose that a major league baseball game has an average length of 2.9 hours with a standard deviation of 0.5 hours. It is known that game length is not normally distributed. Suppose a random sample of 36 games is taken from the population. What is the approximate probability that average game length will be greater than 3.15 hours or less than 2.75 hours? Round to the nearest thousandth.

(Short Answer)

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Question 33

Suppose that the process of drawing samples of size 30 from the population of all maleparticipants is repeated 100 times. If possible, sketch and describe what the samplingdistribution of the means will look like and state the approximate mean value of thedistribution. Round to the nearest thousandth.

(Essay)

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Question 34

A researcher wants to know if mood is affected by music. She conducts a test on a sample of 4 randomly selected adults and measures mood rating before and after being exposed to classic rock Music. Test the hypothesis that mood rating decreased after being exposed to classic rock music. Following are the mood ratings for the four participants: Before exposure After exposure Participant \#1 5.1 5.2 Participant \#2 4.3 4.0 Participant \#3 2.5 2.5 Participant \#4 4.9 4.0 Assume that all conditions for testing have been met. Report the null and alternative hypothesis and p-value. At the $5 \%$ significance level, state your decision regarding the null hypothesis and your conclusion about the original claim. Round all values to the nearest thousandth.

(Multiple Choice)

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Question 35

Use the following information to answer the question. A sprint duathlon consists of a 5 km run, a 20 km bike ride, followed by another 5 km run. The mean finish time of all participants in a recent large duathlon was 1.67 hours with a standard deviation of 0.25 hours. Suppose a random sample of 30 participants was taken and the mean finishing time was found to be 1.59 hours with a standard deviation of 0.30 hours. -In this example, the numerical values of 1.67 hours and 0.25 hours are .

(Multiple Choice)

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Question 36

A chewing gum manufacturer wants to know whether students score higher on math testswhen they are allowed to chew gum during a test. He conducts an experiment with asample of four randomly selected students and records the test results with gum chewingand without. Test the hypothesis that test scores were higher when students were allowedto chew gum during the test. Following are the test scores for the four participants: Without gum With gum Participant \#1 79 80 Participant \#2 95 94 Participant \#3 85 87 Participant \#4 82 84

(Essay)

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Question 37

Use the following information to answer the question. Many couples believe that it is getting too expensive to host an "average" wedding in the United States. According to the website www.costofwedding.com, the average cost of a wedding in the U.S. in 2009 was $24,066. Recently, in a random sample of 40 weddings in the U.S. it was found that the average cost of a wedding was $23,224, with a standard deviation of $2,903. On the basis of this, a 95% confidence interval for the mean cost of weddings in the U.S. is $22,296 to $24,152. -For this description, which of the following does not describe a condition for a valid confidence interval?

(Multiple Choice)

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Question 38

Choose the statement that best describes what is meant when we say that the sample mean is unbiased when estimating the population mean.

(Multiple Choice)

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Question 39

Explain what is meant when we say that the sample mean is an unbiased estimator.

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Question 40

Showing 21 - 40 of 60

Calculate the standard error for the mean finish time of 30 randomly selected male participants. Show all your work and round to the nearest thousandth.

Choose the statement that describes a situation where a confidence interval and a hypothesis test will yield the same results.

Verify that the conditions for a valid confidence interval are met.

Choose the statement that best describes what is meant when we say that the sample mean is unbiased when estimating the population mean.

Explain what is meant when we say that the sample mean is an unbiased estimator.

Introduction to Data

Picturing Variation With Graphs

Numerical Summaries of Center and Variation

Regression Analysis: Exploring Associations Between Variables

Modeling Variation With Probability

Modeling Random Events: the Normal and Binomial Models

Survey Sampling and Inference

Hypothesis Testing for Population Proportions

Associations Between Categorical Variables

Multiple Comparisons and Analysis of Variance

Experimental Design: Controlling Variation

Inference Without Normality

Inference for Regression

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