STAT 200 Week 8 Homework | (5 Questions Answered)
Lane – Ch. 15
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-year-olds
16-year-olds
30 minutes
66
74
68
71
59
67
72
82
46
76
60 minutes
69
95
61
92
69
95
73
98
61
94
Illowsky – Ch. 13
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 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.
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
x-bar =
________
________
________
________
________
s^2 =
________
________
________
________
________
H0:µ1=µ2=µ3=µ4=µ5
Hα: At least any two of the group meansµ1,µ2, …,µ5are not equal.
61. degrees of freedom – numerator: df(num) = ________
63. F static = ________
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 13.24 shows 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 13.26 shows 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
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 (middles incomes)
Professional (wealthy)
17.8
16.5
8.5
26.7
17.4
6.3
49.4
22
4.6
9.4
7.4
12.6
65.4
9.4
11
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 13.34 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