1. A simple random sample of size n from an infinite population of size N is to be selected. Each possible sample should have _____of being selected.

a.

a probability of 1/N

b.

the same probability

c.

a probability of 1/n

d.

a probability of N/n

2. A probability sampling method in which we randomly select one of the first k elements and then select every k^th element thereafter is _____sampling.

a.

stratified random

b.

systematic

c.

convenience

d.

cluster

3. In interval estimation, as the sample size becomes larger, the interval estimate

a.

gets closer to 1.96.

b.

becomes narrower.

c.

becomes wider.

d.

remains the same, because the mean is not changing.

4. When s is used to estimate , the margin of error is computed by using the

a.

t distribution.

b.

mean of the sample.

c.

mean of the population.

d.

normal distribution.

5. From a population with a variance of 484, a sample of 256 items is selected. At 95% confidence, the margin of error is

a.

16.

b.

22.

c.

2.695.

d.

1.375.

6. In order to determine an interval for the mean of a population with unknown standard deviation, a sample of 58 items is selected. The mean of the sample is determined to be 36. The associated number of degrees of freedom for reading the t value is

a.

58.

b.

36.

c.

35.

d.

57.

7. If we want to provide a 95% confidence interval for the mean of a population, the confidence coefficient will be

a.

1.96.

b.

.95.

c.

.485.

d.

1.645.

8. A random sample of 1000 people was taken. Seven hundred fifty of the people in the sample favored Candidate A. The 95% confidence interval for the true proportion of people who favor Candidate A is

a.

.725 to .775.

b.

.70 to .80.

c.

.727 to .773.

d.

.723 to .777.

9. A machine that produces a major part for an airplane engine is monitored closely. In the past, 6% of the parts produced would be defective. With a .95 probability, the sample size that needs to be taken if the desired margin of error is .04 or less is

a.

70.

b.

135.

c.

69.

d.

136.

10. In a sample of 400 voters, 360 indicated they favor the incumbent governor. The 95% confidence interval of voters not favoring the incumbent is

a.

.071 to .129.

b.

.765 to .835.

c.

.120 to .280.

d.

.871 to .929.