Answer: There is sufficient evidence to support the claim that the population standard deviation is less than 0.0410 g. 26
Question: What do the minting-process hypothesis-test results suggest about the new process?
Answer: The new minting process appears to be better than the old method, since there is evidence that the weights of coins produced by the process have a significantly lower variance. 27
Question: For the pulse-rate test of the claim that men’s pulse rates have a standard deviation equal to 10 bpm, identify the null and alternative hypotheses.
Answer: H 0 :σ=10 H 1 :σ =10 28
Question: What is the conclusion for the hypothesis test of whether men’s pulse rates have a standard deviation of 10 bpm, and what does it suggest about using the range rule of thumb?
Answer: Reject the null hypothesis. There is sufficient evidence to warrant rejection of the claim that the standard deviation is 10 bpm. There is significant evidence that using the range rule of thumb with the 60–100 bpm “normal range” is not effective in this case. 29
Question: Which of the following is NOT a requirement for testing a claim about a standard deviation or variance?
Answer: A. The population must be skewed to the right. 30
Question: In general, what does it mean to “resample” a data set?
Answer: D. A sample of the same size is randomly selected from the given sample. 31
Question: When resampling, is sampling done with replacement or without replacement, and why?
Answer: A. Resampling is done with replacement, since resampling without replacement would always result in the same generated sample, which would not be useful. 32
Question: When testing a claim about a proportion, mean, or standard deviation, what are important advantages of resampling methods over parametric methods? Select all that apply.
Answer: C and D. 33
Question: Which probability statement is NOT true?
Answer: D. For any event E, 0<P(E)<1. The correct general rule is 0≤P(E)≤1. 34
Question: The ______ distribution is used to develop confidence interval estimates of variances or standard deviations.
Answer: C. Chi-square 35
Question: For the sample of 15 children’s-movie tobacco-use times, what is a bootstrap sample?
Answer: E. 15 of the times in the provided sample, selected randomly with replacement. 36
Question: Express the claim “More than 4.1% of homes have only a landline telephone and no wireless phone” in symbolic form.
Answer: p>0.041 37
Question: A test statistic of z=1.80 is obtained when testing the claim p>0.3. Is the test left-tailed, two-tailed, or right-tailed?
Answer: C. Right-tailed 38
Question: For z=1.80, p>0.3, and α=0.05, should H 0be rejected?
Answer: Reject H 0 . 39
Question: If a hypothesis test has a P-value of 0.0257 and α=0.05, what conclusion should be made about the null hypothesis?
Answer: C. Reject H 0 because the P-value is less than or equal to α. 40
Question: For the hypothesis that the percentage of adults who have a job is less than 88%, identify the Type I error.
Answer: D. Reject the null hypothesis that the percentage of adults who have a job is equal to 88% when that percentage is actually equal to 88%. 1