# The same statistic equation is used to calculate a value for a

1. The same statistic equation is used to calculate a value for a hypothesis test and for estimation. What value is calculated for each?

a. The hypothesis test calculates a t value and estimation calculates a sample statistic.

b. The hypothesis test calculates a t value and estimation calculates a population parameter.

c. The hypothesis test calculates a a=sample statistic and estimation calculates a t value.

d. The hypothesis test calculates a sample statistic and estimation calculates a t value.

The hypothesis test calculates a population parameter and estimation calculates a t value.

2. A hypothesis test and estimation can both be used to address a question about a treatment effect. What question is addressed by each?

a. Both ask whether the treatment has any effect.

b. both ask how much effect the treatment has.

c. The hypothesis test asks whether there is any effect and estimation asks how much.

d. Estimation asks whether there is any effect and the hypothesis test asks how much.

3. Which of the following accurately represents the general equation for an interval estimate?

a. statistic = parameter ±error

b. statistic = parameter x error

c. parameter = statistic ±error

d. error = parameter ±±statistic

4. If a sample of n=16 scores is being used to make a point estimate of the population mean, µ, what value of t should be used?

a. t = 0

b. t = ±2.131

c. t = ±1.753

d. t = ±1.341

5. If a sample of n = 16 scores is being used to make an 80% confidence interval estimate of the population mane, µ, what value of t should be used?

a. t = 0

b. t = ±2.131

t = ±1.753

d. t = ±1.341

6. If two samples, each with n = 15, are used to estimate the difference between two population means, what values of t would be used to construct a 90% confidence interval?

a. ±1.311

b. ±1.699

c. ±1.313

d. ±1.701

7. Using an independent-measures t, the 90% confidence interval for the difference between two population mean ranges from 19 to 23. Based on this confidence interval, you can conclude that the difference between the two sample means is __________________.

a. 4 points

b. 19 points

c. 21 points

d. 23 points

8. If the sample size is kept constant, which of the following would produce the widest confidence interval for the population mean difference for a repeated-measures study?

a. Md = 5 with 80% confidence

b. Md = 5 with 90% confidence

c. Md = 3 with 90% confidence

d. Md = 3 with 95% confidence

9. Which combination of factors would definitely reduce the width of the confidence interval?

a. use a larger sample and increase the level of confidence

b. use a smaller sample and increase the level of confidence

c. use a larger sample and decease the level of confidence

d. use a smaller sample and decrease the level of confidence

10. If other factors are held constant, what happens to a confidence interval if the size of the sample increases?

a. The standard error decreases and the width of the interval increases.

b. The standard error decreases and the width of the interval decreases.

c. The standard error increases and the width of the interval decreases.

d. The standard error increases and the width of the interval increases.

Problems

1. Describe the difference between point estimates and interval estimates in terms of their confidence and precision in estimating µ.

2. A researcher obtained the following data measuring performance for a group of n =5 participants before and after they received a 30-minute training session. Use the data to make a 90% confidence interval estimate of the population mean improvement in performance following the treatment.

Participant Before After

A 63 73

B 70 69

C 57 59

D 66 74

E 72 78