STATS 200 - Week 8

STATS 200 - WEEK 8 – Homework

1. Exercise #10, Lane Chp 15, Pg 573

If an experiment is conducted with 5 conditions and 6 subjects in each condition, what are dfn and dfe?

2. Exercise #17, Lane Chp 15, Pg 574

The following data are from a hypothetical study on the effects of age and time on scores on a test of reading comprehension. Compute the analysis of variance summary table.

(Use: ADHD Treatment (AT) case study link below for exercises #28 / #29)

Case Study found at:http://onlinestatbook.com/2/case_studies/adhd.html

3. Exercise #28, Lane Chp 15, Pg 577

(AT) The dataset ADHD Treatment has four scores per subject. a. Is the design between-subjects or within-subjects? b. Create an ANOVA summary table.

4. Exercise #29, Lane Chp 15, Pg 577

(AT) Using the Anger Expression Index from the Angry Moods study as the dependent variable, perform a 2x2 ANOVA with gender and sports participation as the two factors. Do athletes and non-athletes differ significantly in how much anger they express? Do the genders differ significantly in Anger Expression Index? Is the effect of sports participation significantly different for the two genders?

((Use the information below to answer exercises #61 / 63))

Suppose a group is interested in determining whether teenagers obtain their drivers licenses at approximately the same average age across the country. Suppose that the following CHAPTER 13 | F DISTRIBUTION AND ONE-WAY ANOVA 723 data are randomly collected from five teenagers in each region of the country. The numbers represent the age at which teenagers obtained their drivers licenses.

H0: ?1 = ?2 = ?3 = ?4 = ?5

H?: At least any two of the group means ?1, ?2, …, ?5 are not equal.

5. Exercise #61, Illowsky Chp 13, Pg 716

Degrees of freedom – numerator: df(num) = _________

6. Exercise #63, Illowsky Chp 13, Pg 716

F statistic = ________

7. Exercise #69, Illowsky Chp 13, Pg 717

A researcher wants to know if the mean times (in minutes) that people watch their favorite news station are the same. Suppose that table below shows the results of a study. 

Assume that all distributions are normal, the four population standard deviations are approximately the same, and the data were collected independently and randomly. Use a level of significance of 0.05.

CNN

FOX

Local

45

15

72

12

43

37

18

68

56

38

50

60

23

31

51

35

22

8. Exercise #71, Illowsky Chp 13, Pg 718

Are the mean number of times a month a person eats out the same for whites, blacks, Hispanics and Asians? Suppose that the table below shows the results of a study. 

Assume that all distributions are normal, the four population standard deviations are approximately the same, and the data were collected independently and randomly. Use a level of significance of 0.05.

White

Black

Hispanic

Asian

6

4

7

8

8

1

3

3

2

5

5

5

4

2

4

1

6

6

7

9. Exercise #77, Illowsky Chp 13, Pg 721-722

A grassroots group opposed to a proposed increase in the gas tax claimed that the increase would hurt working-class people the most, since they commute the farthest to work. Suppose that the group randomly surveyed 24 individuals and asked them their daily one-way commuting mileage. The results are as follows.

Determine whether or not the variance in mileage driven is statistically the same among the working class and professional (middle income) groups. Use a 5% significance level.

Working-class

Professional (mid incomes)

Professional (wealthy)

17. 1

6.5

8.5

26.7

17.4

6.3

49.4

22.0

4.6

9.4

7.4

12.6

65.4

9.4

11.0

47.1

2.1

28.6

19.5

6.4

15.4

51.2

13.9

9.3

10. Exercise #81, Illowsky Chp 13, Pg 723

Is the variance for the amount of money, in dollars, that shoppers spend on Saturdays at the mall the same as the variance for the amount of money that shoppers spend on Sundays at the mall? Suppose that the table below shows the results of a study.

Saturday

Sunday

Saturday

Sunday

75

44

62

137

18

58

0

82

150

61

124

39

94

19

50

127

62

99

31

141

73

60

118

73

89