Week 8
10. If an experiment is conducted with 5 conditions and 6 subjects in each condition, what are dfn and dfe?
17. 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.
12 years old
16 years old
30
66
68
59
72
46
74
71
67
82
76
60
69
61
69
73
61
95
92
95
98
94
28. ADHD Treatment (AT) case study 28. (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.
29. (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 following information to answer the next three exercises. 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
Northeast
SOUTH
WEST
CENTRAL
EAST
16.3
16.9
16.4
16.2
17.1
16.1
16.5
16.5
16.6
17.2
16.4
16.4
16.6
16.5
16.6
16.5
16.2
16.1
16.4
16.8
H0:µ1 =µ2 =µ3 =µ4 =µ5
Hα: At least any two of the group means µ1,µ2, …,µ5 are not equal.
61. degrees of freedom – numerator: df(num) = _________
63. Fstatistic = ________
69. A researcher wants to know if the mean times (in minutes) that people watch their favorite news station are the same. Suppose that Table 13.24shows the results of a study.
CNN
FOX
LOCAL
45
15
72
12
43
37
18
68
56
38
50
60
23
31
51
35
22
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.
71. Are the mean number of times a month a person eats out the same for whites, blacks, Hispanics and Asians? Suppose that Table 13.26shows the results of a study
WHITE
BLACK
HISPANIC
ASIAN
6
4
7
8
8
1
3
3
2
5
5
5
4
2
4
1
6
6
7
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.
77. 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.
WORKING CLASS
PROFESSIONAL MIDDLE CLASS
PROFESSIONAL WEALTHY
17.8
16.5
8.5
26.7
17.4
6.3
49.5
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
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.
81 .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 13.34showstheresults 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
