data analysis chapter 11 study guide

39. A researcher reduces her level of confidence from 99% to 90%. What will happen to the precision of her estimate? (pg 824 tb) A) The estimate will be more precise. B) The estimate will be less precise. C) The precision of her estimate will not change. D) It depends on the size of the population.

A) The estimate will be more precise.

38. The smaller the level of confidence, the ________ precise the estimate. (pg 824 tb) A) more B) less

A) more

36. The larger the level of confidence, the ________ precise the interval estimate. (pg 824 tb) A) more B) less

B) less

8. If the value stated by a null hypothesis is ________ the confidence interval, then the decision would likely be to reject the null hypothesis. (pg 800 tb) A) inside B) outside

B) outside

23. In a sample of 12 participants, a researcher estimates the 80% CI for a sample with a mean of M = 22.3 and an estimated standard error () of 4.7. What is the confidence interval at this level of confidence? A) 80% CI 12.1, 32.5 B) 80% CI 17.6, 27.0 C) 80% CI 15.9, 28.7 D) There is not enough information to answer this question.

C) 80% CI 15.9, 28.7

1. A statistical procedure in which a sample statistic is used to estimate the value of an unknown population parameter is called (slide 4 ppt) (pg. 785 tb) A) an educated guess B) appropriation C) estimation D) significance testing

estimation

11. If the null hypothesis is inside the confidence interval, then the decision was likely to ________ using hypothesis testing. (pg 800 tb) A) reject the null hypothesis B) retain the null hypothesis

B) retain the null hypothesis

30. Which type of error is used to compute the confidence interval for two related samples selected from at least one population with an unknown variance? (pg 803 tb) A) standard error B) estimated standard error C) estimated standard error for the difference D) estimated standard error for the difference scores

D) estimated standard error for the difference scores

19. The confidence interval for samples selected from a population with an unknown variance is computed using critical values from the t table. This is true for which of the following types of samples? A) one-sample B) two-independent sample C) related samples D) all of the above

D) all of the above

40. Which of the following words best describes certainty? (pg 824 tb) A) inferential B) significance C) precision D) confidence

D) confidence

6. A researcher reports that college students consume an average of 3.6 alcoholic drinks per week. What is the interval estimate in this example? (pg 788 tb) A) 3.6 B) The interval estimate is not given.

B) The interval estimate is not given.

20. Which type of error is used to compute the confidence interval for one sample selected from a population with an unknown variance? (pg 803 tb) A) standard error B) estimated standard error C) estimated standard error for the difference D) estimated standard error for the difference scores

B) estimated standard error

28. In a sample of 30 participants, a researcher estimates the 95% CI for a sample with a mean of = 0.7 and an estimated standard error for the difference () of 0.2. What is the confidence interval at this level of confidence? A) 95% CI 0.4, 1.0 B) 95% CI 0.5, 0.9 C) 95% CI 0.3, 1.1 D) There is not enough information to answer this question.

C) 95% CI 0.3, 1.1

25. Which type of error is used to compute the confidence interval for two independent samples selected from at least one population with an unknown variance? (pg 803 tb) A) standard error B) estimated standard error C) estimated standard error for the difference D) estimated standard error for the difference scores

C) estimated standard error for the difference

34. In a sample of 17 participants, a researcher estimates the 90% CI for a sample with a mean of = 7 and an estimated standard error for the difference scores () of 2.2. What is the confidence interval at this level of confidence? A) 90% CI 2.4, 11.6 B) 90% CI 3.2, 10.8 C) 90% CI 4.8, 9.2 D) There is not enough information to answer this question.

B) 90% CI 3.2, 10.8

29. In a sample of 14 participants, a researcher estimates the 90% CI for a sample with a mean of = 10.7 and an estimated standard error for the difference () of 2.9. What is the confidence interval at this level of confidence? A) 90% CI 4.4, 17.0 B) 90% CI 5.5, 15.9 C) 90% CI 7.8, 13.6 D) There is not enough information to answer this question.

B) 90% CI 5.5, 15.9

26. In a sample of 18 participants, a researcher estimates the 80% CI for a sample with a mean of = 8.8 and an estimated standard error for the difference () of 1.8. What is the upper confidence limit for this interval? A) 6.4 B) 7.0 C) 10.6 D) 11.2

D) 11.2

31. In a sample of 26 participants, a researcher estimates the 90% CI for a sample with a mean of = 0.6 and an estimated standard error for the difference scores () of 1.1. What is the upper confidence limit for this interval? (pg 820 tb) A) -1.3 B) -0.5 C) 1.7 D) 2.5

D) 2.5

5. A researcher reports with 90% confidence that 31% to 37% of Americans believe in ghosts. What is the point estimate for this interval? (pg 788 tb) A) 31% B) 34% C) 37% D) 31% to 37%

B) 34%

9. A researcher concludes that stress levels are higher following a major versus a minor traffic accident (95% confidence interval [CI] 1.86-3.02). If the null hypothesis stated that there would be no difference (null hypothesis: µ = 0), then what is the effect size for this confidence interval? A) Between 1.86% and 3.02% of the variability in stress levels can be accounted for by type of traffic accident. B) Ratings of stress shifted more than 1.86 points in the population. C) Ratings of stress shifted between 1.86 and 3.02 points in the population. D) There is not enough information to answer this question.

C) Ratings of stress shifted between 1.86 and 3.02 points in the population.

22. In a sample of 20 participants, a researcher estimates the 95% CI for a sample with a mean of M = 5.4 and an estimated standard error () of 1.6. What is the lower confidence limit for this interval? A) 2.1 B) 3.8 C) 7.0 D) 8.8

A) 2.1

35. Which of the following is a characteristic of confidence intervals? (pg 824 tb) A) The less certain an estimate, the more precise the estimate. B) The more certain an estimate, the less precise the estimate. C) both A and B

C) both A and B

10. A researcher compares the height of male executives in the U.S. to the average height of males (µ = 67 inches). He determines that the average height of male executives is 70 inches (95% confidence interval [CI] 68-72). Based on this result, what would the decision have been for a hypothesis test? (pg 800 tb) A) Reject the null hypothesis. B) Retain the null hypothesis. C) There is not enough information to answer this question.

A) Reject the null hypothesis.

13. The confidence interval for one sample selected from a population with a known variance is computed using a critical value for which type of test? (pg 794 tb) A) z test B) t test C) none D) both A and B

A) z test

17. A researcher estimates the 90% CI for a sample with a mean of M = 8.9 and a standard error () of 2.1. What is the confidence interval at this level of confidence? (pg 801 tb) A) 90% CI 4.8, 13.0 B) 90% CI 5.5, 12.4 C) 90% CI 6.8, 11.0 D) There is not enough information to answer this question.

B) 90% CI 5.5, 12.4

2. Which of the following best describes the goal of estimation? (slide 4 ppt) (pg 786 ppt) A) to determine the extent to which a result is significant B) to estimate the significance of a result C) to narrow in on the true population mean by defining limits within which it is likely to be contained D) both A and B

C) to narrow in on the true population mean by defining limits within which it is likely to be contained

7. If the value stated by a null hypothesis is ________ the confidence interval, then the decision would have likely been to retain the null hypothesis. (pg 800 tb) A) inside B) outside

A) inside

12. If the null hypothesis is outside the confidence interval, then the decision was likely to ________ using hypothesis testing. (pg 800 tb) A) reject the null hypothesis B) retain the null hypothesis

A) reject the null hypothesis

14. Which type of error is used to compute the confidence interval for one sample selected from a population with a known variance? A) standard error B) estimated standard error C) estimated standard error for the difference D) estimated standard error for the difference scores

A) standard error

27. In a sample of 18 participants, a researcher estimates the 80% CI for a sample with a mean of = 8.8 and an estimated standard error for the difference () of 1.8. What is the lower confidence limit for this interval? A) 6.4 B) 7.0 C) 10.6 D) 11.2

A) 6.4

37. A researcher increases his level of confidence from 90% to 95%. What will happen to the precision of his estimate? (pg 824 tb) A) The estimate will be more precise. B) The estimate will be less precise. C) The precision of his estimate will not change. D) It depends on the size of the population.

B) The estimate will be less precise.

4. A point estimate is typically reported with an interval estimate. Why? (pg 788 tb) A) Using only a point estimate is associated with low certainty. B) The interval estimate gives researchers a higher level of confidence. C) The interval estimate adds certainty to the estimate of the population mean. D) all of the above

D) all of the above

15. A researcher estimates the 95% CI for a sample with a mean of M = 3.26 and a standard error () of 0.91. What is the upper confidence limit for this interval? (pg 800 tb) A) 1.48 B) 2.35 C) 4.17 D) 5.04

D) 5.04

21. In a sample of 20 participants, a researcher estimates the 95% CI for a sample with a mean of M = 5.4 and an estimated standard error () of 1.6. What is the upper confidence limit for this interval? (pg 803 tb) A) 2.1 B) 3.8 C) 7.0 D) 8.8

D) 8.8

32. In a sample of 26 participants, a researcher estimates the 90% CI for a sample with a mean of = 0.6 and an estimated standard error for the difference scores () of 0.1. What is the upper confidence limit for this interval? A) 0.77 B) -0.5 C) 1.7 D) 2.5

A) 0.77

16. A researcher estimates the 95% CI for a sample with a mean of M = 3.26 and a standard error () of 0.91. What is the lower confidence limit for this interval? (pg 800 tb) A) 1.48 B) 2.35 C) 4.17 D) 5.04

A) 1.48

24. In a sample of 28 participants, a researcher estimates the 95% CI for a sample with a mean of M = 1.5 and an estimated standard error () of 0.3. What is the confidence interval at this level of confidence? A) 95% CI 1.0, 2.0 B) 95% CI 1.2, 1.8 C) 95% CI 0.9, 2.1 D) There is not enough information to answer this question.

C) 95% CI 0.9, 2.1

18. A researcher estimates the 95% CI for a sample with a mean of M = 9.0 and a standard error () of 1.03. What is the confidence interval at this level of confidence? A) 95% CI 7.3, 10.7 B) 95% CI 8.0, 10.0 C) 95% CI 7.0, 11.0 D) There is not enough information to answer this question.

C) 95% CI 7.0, 11.0

33. In a sample of 20 participants, a researcher estimates the 99% CI for a sample with a mean of = 3.7 and an estimated standard error for the difference scores () of 0.2. What is the confidence interval at this level of confidence? A) 99% CI 3.5, 3.9 B) 99% CI 3.2, 4.2 C) 99% CI 3.1, 4.3 D) There is not enough information to answer this question.

C) 99% CI 3.1, 4.3

3. Which of the following explains why point estimation can be a useful procedure to estimate a population mean? (pg 788 tb) A) It defines the range of scores within which the population mean is likely to be contained. B) The sample mean is equal to the population mean on average. C) The sample mean is an unbiased estimator of the population mean. D) both B and C

D) both B and C