Stats 200

Decide whether the following statements are true or false.

70. The standard deviation of the chi-square distribution is twice the mean.

102. Do men and women select different breakfasts? The breakfasts ordered by randomly selected men and women at a popular breakfast place is shown in Table 11.55. Conduct a test for homogeneity at a 5% level of significance.

113. df = ________

Use the following information to answer the next twelve exercises: Suppose an airline claims that its flights are consistently

on time with an average delay of at most 15 minutes. It claims that the average delay is so consistent that the variance is no

Table 11.55

French Toast

Pancakes

Waffles

Omelettes

Men

47

35

28

53

Women

65

55

55

60

Color

Texture

Ligth

Meduim

Dark

FIne

4

20

8

Medium

5

23

12

Coarse

21

23

4

more than 150 minutes. Doubting the consistency part of the claim, a disgruntled traveler calculates the delays for his next

25 flights. The average delay for those 25 flights is 22 minutes with a standard deviation of 15 minutes.

66. Can a coefficient of determination be negative? Why or why not?

14. A geologist collects hand-specimen sized pieces of limestone from a particular

area. A qualitative assessment of both texture and color is made with the

following results. Is there evidence of association between color and texture for

these limestones? Explain your answer.