STAT200 Week 8 Homework questions

Question: #5415

There are 8 questions. Required full solutions showing work/formulas and any tables/calulators/excell formulas that are used to solve the problem.

LANE

Chp 15 10) 573

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

17) 574

2. 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.

30 minutes 12 year olds 16 year olds

66 74

68 71

59 67

72 82

46 76

60 Minutes 69 95

61 92

69 95

73 98

61 94

ILLOWSKY

Chp 13 61) 716

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¯ =

s ² =

H0: µ1 = µ2 = µ3 = µ4 = µ5

Hα: At least any two of the group means µ1, µ2, …, µ5 are not equal.

3. 61. degrees of freedom – numerator: df(num) = _________ (show work)

63) 716

4. 63. F statistic = ________ (show work

69) 717

5. 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) 718

6. 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) 721

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 (Middle Class) Professional (Wealthy)

17.8 16.5 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

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) 722

8. 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 29

94 19 50 127

62 99 31 141

73 60 118 73