1. Active Learning Lecture Slides For use with Classroom Response Systems Statistical Inference: Confidence Intervals

2. Copyright © 2013 Pearson Education, Inc. 8.1 A good point estimate has which of the following characteristics? a) Bias: None Standard Error: High b) Bias: High Standard Error: High c) Bias: None Standard Error: Low d) Bias: High Standard Error: Low

3. Copyright © 2013 Pearson Education, Inc. 8.1 A good point estimate has which of the following characteristics? a) Bias: None Standard Error: High b) Bias: High Standard Error: High c) Bias: None Standard Error: Low d) Bias: High Standard Error: Low

4. Copyright © 2013 Pearson Education, Inc. 8.2 When the sampling distribution is approximately normal, what is the margin of error equal to for a 95% confidence interval? a) 1.96 b) 1.96*standard error c) Standard error d) Point estimate 1.96*standard error

5. Copyright © 2013 Pearson Education, Inc. a) 1.96 b) 1.96*standard error c) Standard error d) Point estimate 1.96*standard error 8.2 When the sampling distribution is approximately normal, what is the margin of error equal to for a 95% confidence interval?

6. Copyright © 2013 Pearson Education, Inc. 8.3 In 2006 the GSS had a special topic that investigated disabilities. They asked respondents if they had difficulty fully participating in school, housework or other daily activities and 265 out of 2,749 said “yes”. What is the point estimate of the population proportion of Americans that have difficulty completing these tasks? a) 0.10 b) 0.097 c) 0.265 d) p e) Unknown

7. Copyright © 2013 Pearson Education, Inc. a) 0.10 b) 0.097 c) 0.265 d) p e) Unknown 8.3 In 2006 the GSS had a special topic that investigated disabilities. They asked respondents if they had difficulty fully participating in school, housework or other daily activities and 265 out of 2,749 said “yes”. What is the point estimate of the population proportion of Americans that have difficulty completing these tasks?

8. Copyright © 2013 Pearson Education, Inc. 8.4 True or False: A point estimate is better than an interval estimate because it gives you the exact value for which you are looking. a) True b) False

9. Copyright © 2013 Pearson Education, Inc. 8.4 True or False: A point estimate is better than an interval estimate because it gives you the exact value for which you are looking. a) True b) False

10. Copyright © 2013 Pearson Education, Inc. 8.5 True or False: An interval estimate gives you a region that the parameter has to fall within. a) True b) False

11. Copyright © 2013 Pearson Education, Inc. 8.5 True or False: An interval estimate gives you a region that the parameter has to fall within. a) True b) False

12. Copyright © 2013 Pearson Education, Inc. 8.6 The formula below gives a region of plausible values of : a) the population proportion b) the population mean c) the sample mean d) the sample proportion

13. Copyright © 2013 Pearson Education, Inc. 8.6 The formula below gives a region of plausible values of : a) the population proportion b) the population mean c) the sample mean d) the sample proportion

14. Copyright © 2013 Pearson Education, Inc. 8.7 In 2006 the GSS asked 2,986 people if they were very happy, pretty happy, or not too happy and 920 people said that they were very happy. Is the sample “large” enough to calculate the 95% confidence interval to estimate the proportion of all Americans that are very happy? a) Yes, there are more than 30 observations. b) Yes, there are more than 15 successes and 15 failures. c) No, there are not more than 15 successes and 15 failures. d) Cannot be determined.

15. Copyright © 2013 Pearson Education, Inc. 8.7 In 2006 the GSS asked 2,986 people if they were very happy, pretty happy, or not too happy and 920 people said that they were very happy. Is the sample “large” enough to calculate the 95% confidence interval to estimate the proportion of all Americans that are very happy? a) Yes, there are more than 30 observations. b) Yes, there are more than 15 successes and 15 failures. c) No, there are not more than 15 successes and 15 failures. d) Cannot be determined.

16. Copyright © 2013 Pearson Education, Inc. 8.8 In 2006 the GSS asked 2,986 people if they were very happy, pretty happy, or not too happy and 920 people said that they were very happy. Find the 95% confidence interval to estimate the proportion of all Americans that are very happy. a) (0, 0.02) b) (0.25, 0.37) c) (0.27, 0.35) d) (0.29, 0.32)

17. Copyright © 2013 Pearson Education, Inc. 8.8 In 2006 the GSS asked 2,986 people if they were very happy, pretty happy, or not too happy and 920 people said that they were very happy. Find the 95% confidence interval to estimate the proportion of all Americans that are very happy. a) (0, 0.02) b) (0.25, 0.37) c) (0.27, 0.35) d) (0.29, 0.32)

18. Copyright © 2013 Pearson Education, Inc. 8.10 Based off of the same sample, which of the confidence intervals for the population mean would be the widest? a) A 90% confidence interval b) A 95% confidence interval c) A 99% confidence interval d) Cannot be determined

19. Copyright © 2013 Pearson Education, Inc. 8.10 Based off of the same sample, which of the confidence intervals for the population mean would be the widest? a) A 90% confidence interval b) A 95% confidence interval c) A 99% confidence interval d) Cannot be determined

20. Copyright © 2013 Pearson Education, Inc. 8.11 The margin of error of a confidence interval of the population mean decreases as… a) the sample size decreases. b) the sample size increases. c) the sample mean increases. d) the sample mean decreases.

21. Copyright © 2013 Pearson Education, Inc. 8.11 The margin of error of a confidence interval of the population mean decreases as… a) the sample size decreases. b) the sample size increases. c) the sample mean increases. d) the sample mean decreases.

22. Copyright © 2013 Pearson Education, Inc. 8.12 The General Social Survey included a question about how many hours the respondent spent doing religious activities outside of their own home. For the 1,414 respondents the sample mean was 6.15 hours and the sample standard deviation was 16.53 hours. Find the 95% confidence interval for the population mean amount of time spent doing religious activities outside of their own home. a) (5.43, 6.87) b) (-26.24, 38.55) c) (5.29, 7.01) d) (5.03, 7.27)

23. Copyright © 2013 Pearson Education, Inc. 8.12 The General Social Survey included a question about how many hours the respondent spent doing religious activities outside of their own home. For the 1,414 respondents the sample mean was 6.15 hours and the sample standard deviation was 16.53 hours. Find the 95% confidence interval for the population mean amount of time spent doing religious activities outside of their own home. a) (5.43, 6.87) b) (-26.24, 38.55) c) (5.29, 7.01) d) (5.03, 7.27)

24. Copyright © 2013 Pearson Education, Inc. 8.13 The General Social Survey included a question about how many hours the respondent spent doing religious activities outside of their own home. For the 1,414 respondents the sample mean was 6.15 hours and the sample standard deviation was 16.53 hours. What can we say about the distribution of hours spent doing religious activities? a) It is bell shaped. b) It is right skewed. c) It is left skewed. d) Nothing can be determined.

25. Copyright © 2013 Pearson Education, Inc. 8.13 The General Social Survey included a question about how many hours the respondent spent doing religious activities outside of their own home. For the 1,414 respondents the sample mean was 6.15 hours and the sample standard deviation was 16.53 hours. What can we say about the distribution of hours spent doing religious activities? a) It is bell shaped. b) It is right skewed. c) It is left skewed. d) Nothing can be determined.

26. Copyright © 2013 Pearson Education, Inc. 8.21 The margin of error of a confidence interval estimates the error… a) caused by bad sampling techniques. b) caused by measurement error. c) caused by not controlling lurking variables. d) caused by using a sample rather than the whole population. e) all of the above.

27. Copyright © 2013 Pearson Education, Inc. 8.21 The margin of error of a confidence interval estimates the error… a) caused by bad sampling techniques. b) caused by measurement error. c) caused by not controlling lurking variables. d) caused by using a sample rather than the whole population. e) all of the above.