1. Describing Distributions with Numbers BPS chapter 2 © 2010 W.H. Freeman and Company

2. 1. Median 1. Find the median of the following 9 numbers: 43 54 55 63 67 68 69 77 85 a) 65 b) 64 c) 67 d) 64.6

3. 1. Median (answer) Find the median of the following 9 numbers: 43 54 55 63 67 68 69 77 85 a) 65 b) 64 c) 67 d) 64.6

4. 2. Median For the data in the previous question, 43 54 55 63 67 68 69 77 85 Suppose that the last data point is actually 115 instead of 85. What effect would this new maximum have on our value for the median of the dataset? a) Increase the value of the median. b) Decrease the value of the median. c) Not change the value of the median.

5. 2. Median (answer) For the data in the previous question, 43 54 55 63 67 68 69 77 85 Suppose that the last data point is actually 115 instead of 85. What effect would this new maximum have on our value for the median of the dataset? a) Increase the value of the median. b) Decrease the value of the median. c) Not change the value of the median.

6. 3. Mean For the data in the previous question, 43 54 55 63 67 68 69 77 85 Suppose that the last data point is actually 115 instead of 85. What effect would this new maximum have on our value for the mean of the dataset? a) Increase the value of the mean. b) Decrease the value of the mean. c) Not change the value of the mean.

7. 3. Mean (answer) For the data in the previous question, 43 54 55 63 67 68 69 77 85 Suppose that the last data point is actually 115 instead of 85. What effect would this new maximum have on our value for the mean of the dataset? a) Increase the value of the mean. b) Decrease the value of the mean. c) Not change the value of the mean.

8. 4. Mean vs. median For the dataset “sales prices of homes in Los Angeles,” should you use the mean or the median to describe the center? a) Mean b) Median

9. 4. Mean vs. median (answer) For the dataset “sales prices of homes in Los Angeles,” should you use the mean or the median to describe the center? a) Mean b) Median

10. 5. Mean vs. median For the dataset “incomes for people in the United States,” should you use the mean or the median to describe the center? a) Mean b) Median

11. 5. Mean vs. median (answer) For the dataset “incomes for people in the United States,” should you use the mean or the median to describe the center? a) Mean b) Median

12. 6. Comparing two histograms Compare the centers of Distribution A (Female Shoulder Girth) and Distribution B (Male Shoulder Girth) shown below. a) The center of Distribution A is greater than the center of Distribution B. b) The center of Distribution A is less than the center of Distribution B. c) The center of Distribution A is equal to the center of Distribution B.

13. 6. Comparing two histograms (answer) Compare the centers of Distribution A (Female Shoulder Girth) and Distribution B (Male Shoulder Girth) shown below. a) The center of Distribution A is greater than the center of Distribution B. b) The center of Distribution A is less than the center of Distribution B. c) The center of Distribution A is equal to the center of Distribution B.

14. 7. In the data below Ashley has a Z score of.29. That means: A. She is above average B. She is 29% above average C. She is 29 inches above average D. She is 29 dollars richer than the average E. All of the above

15. 7. In the data below Ashley has a Z score of.29. That means: A. She is above average B. She is 29% above average C. She is 29 inches above average D. She is 29 dollars richer than the average E. All of the above

16. 8. Which of the following tells us about the group? A. The raw score B. The Z score C. The deviation score D. The mean E. All of the above

17. 8. Which of the following tells us about the group? A. The raw score B. The Z score C. The deviation score D. The mean E. All of the above

18. 8. Standard deviation Which of the following statements is TRUE? a) Standard deviation has no unit of measurement. b) Standard deviation is either positive or negative. c) Standard deviation is inflated by outliers. d) Standard deviation is used even when the mean is not an appropriate measure of center.

19. 8. Standard deviation (answer) Which of the following statements is TRUE? a) Standard deviation has no unit of measurement. b) Standard deviation is either positive or negative. c) Standard deviation is inflated by outliers. d) Standard deviation is used even when the mean is not an appropriate measure of center.

20. 9. Center and spread For the following distribution of major league baseball players’ salaries in 1992, which measures of center and spread are more appropriate? a) Mean and standard deviation b) Median and interquartile range

21. Center and spread (answer) For the following distribution of major league baseball players’ salaries in 1992, which measures of center and spread are more appropriate? a) Mean and standard deviation b) Median and interquartile range

22. 10. Center and spread Which measure uses all the data? a) Mean b) standard deviation c) Median d) Mode e) A and B

23. 10. Center and spread Which measure uses all the data? a) Mean b) standard deviation c) Median d) Mode e) A and B

24. 11. Which of the following tells us about the individual? A. The raw score B. The Z score C. The deviation score D. The percent correct E. All of the above

25. 11. Which of the following tells us about the individual? A. The raw score B. The Z score C. The deviation score D. The percent correct E. All of the above

26. The End