1. As the margin of error of a confidence interval increases, ___.

a. the population standard deviation decreases.

b. the population standard deviation increases.

c. the sample mean increases.

d. the confidence interval decreases.

2. Suppose the heights of women are normally distributed with a standard deviation of 2.4 inches. Construct a 99% confidence interval for the following heights of four randomly selected women: (63'', 69'', 62'', and 66'').

a.

b.

c.

d.

e.

3. In hypothesis testing, the p-value tells us the ____ level of significance at which the null hypothesis can be ____.

a. largest; rejected

b. smallest; accepted

c. largest; accepted

d. smallest; rejected

4. In a hypothesis test, assuming the null hypothesis is true, the probability that the test statistic will take a value at least as extreme as the value actually observed is ___.

a. the p-value of the test.

b. the critical value of the test.

c. the margin of error of the test.

d. the level of significance of the test.

5. Based on the statement, "We are fairly sure that this new drug can eliminate headaches. Let's put it on the market," you have created the following null and alternative hypotheses: H₀: The drug does not eliminate headaches. H_a: The drug does eliminate headaches. a. Which of the following is the Type II error associated with this scenario?

b. We conclude that the drug eliminates headaches and it really does

c. We conclude that the drug does not eliminate headaches and it really does not

d. We conclude that the drug eliminates headaches when it really does not

e. We conclude that the drug does not eliminate headaches when it really does

6. Based on the statement, "We are fairly sure that this new drug can eliminate headaches. Let's put it on the market," you have created the following null and alternative hypotheses: H₀: The drug does not eliminate headaches. H_a: The drug does eliminate headaches. Which of the following is the Type I error associated with this scenario?

a. We conclude that the drug does not eliminate headaches when it really does

b. We conclude that the drug eliminates headaches when it really does not

c. We conclude that the drug eliminates headaches and it really does

d. We conclude that the drug does not eliminate headaches and it really does not

7. A 90% confidence interval for the mean of a given population is computed from a random sample and found to be . Based on this information, which of the following statements is true about this confidence interval?

a. All of the above statements about confidence intervals are true.

b. 90% of the values sampled are between 8 and 16.

c. There is a 90% confidence that the true mean of the population is between 8 and 16.

d. There is a 90% probability that the true mean of the population is 12 and a 90% probability that the true margin of error is 3.

e. There is a 90% probability thatis between 8 and 16.

8. In hypothesis testing, which of the following would be strong evidence against the null hypothesis?

a. obtaining data with a small p-value

b. using a small significance level

c. using a large significance level

d. obtaining data with a large p-value

e. none of the above is strong evidence against the null hypothesis

9. Which of the following statements about rejecting the null hypothesis is true?

a. If the sample data is such that for a one-tailed test of the mean you can reject H₀ at the 5% level of significance, you can always reject H₀ for a two-tailed test at the 1% level of significance.

b. If the p-value is such that you can reject H₀ for a 5% level of significance, you can always reject it for a 1% level of significance.

c. If the sample data is such that for a one-tailed test of the mean you can reject H₀ at the 1% level of significance, you can always reject H₀ for a two-tailed test at the same level of significance.

d. If the p-value is such that you can reject H₀ for a 1% level of significance, you can always reject it for a 5% level of significance.

10. An article in the newspaper states that the average number of traffic accidents per month involving road rage is higher this year than last year's average of 12.5 accidents per month. State the null and alternate hypotheses.

a.

b.

c.