1. What is the primary reason for applying a finite population correction coefficient?

A. When the sample is a very small portion of the population, the correction coefficient is required.

B. If you don't apply the correction coefficient, you won't have values to plug in for all the variables in the confidence interval

formula.

C. If you don't apply the correction coefficient, your confidence intervals will be too broad, and thus less useful in decision

making.

D. If you don't apply the correction coefficient, your confidence intervals will be too narrow, and thus overconfident.

2. In the statement of a null hypothesis, you would likely find which of the following terms?

A. =

B. >

C. <

D.

3. To schedule appointments better, the office manager for an ophthalmologist wants to estimate the

average time that the doctor spends with each patient. A random sample of 49 is taken, and the sample

mean is 20.3 minutes. Assume that the office manager knows from past experience that the standard

deviation is 14 minutes. She finds that a 95% confidence interval is between 18.3 and 22.3 minutes. What

is the point estimate of the population mean, and what is the confidence coefficient?

A. 20.3, 95%

B. 18.3, 95%

C. 20.3, 0.95

D. 18.3, 0.95

4. H0 is p = 0.45 and H1 is p 0.45. What type of test will be performed?

A. One-tail testing of a mean

B. Two-tail testing of a mean

C. Two-tail testing of a proportion

D. One-tail testing of a proportion

5. Determine the power for the following test of hypothesis.

H0 : = 950 vs. H1 : 950, given that = 1,000, = 0.10, = 200, and n = 25.

A. 0.3465

B. 0.6535

C. 0.5062

D. 0.4938

6. What sample size is required from a very large population to estimate a population proportion within

0.05 with 95% confidence? Don't assume any particular value for p.

A. 385

B. 38

C. 767

D. 271

7. A woman and her son are debating about the average length of a preacher's sermons on Sunday

morning. Despite the mother's arguments, the son thinks that the sermons are more than twenty minutes.

For one year, he has randomly selected 12 Sundays and found an average time of 26.42 minutes with a

standard deviation of 6.69 minutes. Assuming that the population is normally distributed and using a 0.05

level of significance, he wishes to determine whether he is correct in thinking that the average length of

sermons is more than 20 minutes. What is the test statistic?

A. 0.95

B. 3.32

C. 6.69

D. 3.32

8. Which of the following statements correctly compares the t-statistic to the z-score when creating a

confidence interval?

A. The value of z relates to a normal distribution, while the value of t relates to a Poisson distribution.

B. You can use t all the time, but for n 30 there is no need, because the results are almost identical if you use t or z.

C. Using t is easier because you do not have to worry about the degrees of freedom, as you do with z.

D. Use t when the sample size is small, and the resulting confidence interval will be narrower.

9. If the level of significance () is 0.005 in a two-tail test, how large is the nonrejection region under the

curve of the t distribution?

A. 0.005

B. 0.9975

C. 0.995

D. 0.050

10. Consider a null hypothesis stating that the population mean is equal to 52, with the research hypothesis

that the population mean is not equal to 52. Assume we have collected 38 sample data from which we

computed a sample mean of 53.67 and a sample standard deviation of 3.84. Further assume the sample

data appear approximately normal. What is the p-value you would report for this test?

A. 0.0037

B. 0.4963

C. 0.0041

D. 0.0074

11. A human resources manager wants to determine a confidence interval estimate for the mean test score

for the next office-skills test to be given to a group of job applicants. In the past, the test scores have been

normally distributed with a mean of 74.2 and a standard deviation of 30.9. Determine a 95% confidence

interval estimate if there are 30 applicants in the group.

A. 63.14 to 85.26

B. 64.92 to 83.48

C. 68.72 to 79.68

D. 13.64 to 134.76

12. A mortgage broker is offering home mortgages at a rate of 9.5%, but the broker is fearful that this value

is higher than many others are charging. A sample of 40 mortgages filed in the county courthouse shows an

average of 9.25% with a standard deviation of 8.61%. Does this sample indicate a smaller average? Use

= 0.05 and assume a normally distributed population.

A. Yes, because the sample mean of 9.25 is below 9.5.

B. No, because the test statistic falls in the acceptance region.

C. Yes, because the test statistic is greater than 1.645.

D. No, because the test statistic is 1.85 and falls in the rejection region.

13. Which of the following statements about hypothesis testing is false?

A. In both the one-tailed and two-tailed tests, the rejection region is one contiguous interval on the number line.

B. A Type I error is the chance that the researcher rejects the null hypothesis when in fact the null hypothesis is true.

C. The rejection region is always given in units of standard deviations from the mean.

D. The test will never confirm the null hypothesis, only fail to reject the null hypothesis.

14. The power of a test is the probability of making a/an _______ decision when the null hypothesis is

_______.

A. correct, true

B. correct, false

C. incorrect, false

D. incorrect, true

15. In sampling without replacement from a population of 900, it's found that the standard error of the

mean, , is only two-thirds as large as it would have been if the population were infinite in size. What is

the approximate sample size?

A. 600

B. 500

C. 400

D. 200

16. A researcher wants to carry out a hypothesis test involving the mean for a sample of n = 20. While the

true value of the population standard deviation is unknown, the researcher is reasonably sure that the

population is normally distributed. Given this information, which of the following statements would be

correct?

A. The t-test should be used because and are unknown.

B. The t-test should be used because the sample size is small.

C. The researcher should use the z-test because the sample size is less than 30.

D. The researcher should use the z-test because the population is assumed to be normally distributed.

17. For 1996, the U.S. Department of Agriculture estimated that American consumers would have eaten,

on average, 2.6 pounds of cottage cheese throughout the course of that year. Based on a longitudinal study

of 98 randomly selected people conducted during 1996, the National Center for Cottage Cheese Studies

found an average cottage cheese consumption of 2.75 pounds and a standard deviation of s = 14 ounces.

Given this information, which of the following statements would be correct concerning a two-tail test at the

0.05 level of significance?

A. We can conclude that the average cottage cheese consumption in America is at least 0.705 pound more or less than 2.75

pounds per person per year.

B. We can conclude that the average cottage cheese consumption in America is actually 2.75 pounds per person per year.

C. We can conclude that we can't reject the claim that the average cottage cheese consumption in America is 2.6 pounds per

person per year.

D. We can conclude that the average cottage cheese consumption in America isn't 2.6 pounds per person per year.

18. In a simple random sample from a population of several hundred that's approximately normally

distributed, the following data values were collected.

68, 79, 70, 98, 74, 79, 50, 102, 92, 96

Based on this information, the confidence level would be 90% that the population mean is somewhere

between

A. 71.36 and 90.24.

B. 65.33 and 95.33.

C. 73.36 and 88.24.

D. 69.15 and 92.45.

19. Because of the popularity of movies as an entertainment medium for adolescents, an entrepreneur plans

to do a national study of the average cost of a movie ticket. If you assume that s = $0.50, what sample size

would the entrepreneur have to take to be 95% confident that the estimate was within $0.25 of the true

mean ticket prices?

A. 15

B. 8

C. 16

D. 4

20. A random sample of 10 employees is selected from a large firm. For the 10 employees, the number of

days each was absent during the past month was found to be 0, 2, 4, 2, 5, 1, 7, 3, 2, and 4. Of the

following values, which would you use as the point estimate for the average number of days absent for all

the firm's employees?

A. 4

B. 3

C. 30

D. 2.5