10 Statistic Questions

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

2. 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	65	74
	68	71
	59	66
	72	82
	46	76
60 minutes	69	95
	61	92
	69	95
	73	98
	61	94

Please use this link to answer problems 3 and 4.

http://onlinestatbook.com/2/case_studies/adhd.html

3. (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. (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?

13.2 The F Distribution and the F-Ratio

Use the following information to answer questions five and six. 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 719

http://openstaxcollege.org/files/textbook_version/hi_res_pdf/15/col11562-op.pdf

Page 720.

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=	________	________	________	________	________
	________	________	________	________	________

5. degrees of freedom – numerator: df(num) = _________

6. F statistic = ________

7. 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.

8. 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

9. 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 Income	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

10. 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