Statistics for Business: Decision Making and Analysis, 3rd Edition

Chapter 22

Mix and Match

1. 1. i or f

2. 3. f or i

3. 5. b

4. 7. e

5. 9. j

True/False

• 11. False. When the variance of the errors changes, prediction intervals are likely to be too short in some cases and too long in others.

• 13. True

• 15. True

• 17. False. If omitted variables contribute small, independent deviations, their net effect tends to have bell−shaped variation.

• 19. False. The decision to exclude data should account for substantive relevance. An unusual case might be the most important data.

• 21. False. It is easier to see changes in the variation in the plot of residuals on x.

Think About It

• 23. The data would likely have unequal variation, with more variation among larger stores.

• 25. The analyst failed to realize an evident lack of constant variation. ...