Chapter 15.5, Problem 15.51ACI

Public defenders’ salaries. Random samples of seven lawyers employed as public defenders were selected from each of three major cities. Their salaries are recorded in the table on the top of the next column. You have been hired to determine whether differences exist among the salary distributions for public defenders in the three cities.

Atlanta	Los Angeles	Washington, D.C.
$39.600	$47.400	$48.000
89.900	140.000	86.900
66.700	68.000	58.000
43.900	48.700	82.600
82200	74.400	83.200
88.600	102.000	61.800
64.800	54.500	65.000
Source: Based on average salaries reported in www.glassdoor.com.

1. a. Under what circumstances would it be appropriate to use the F-test for a completely randomized design to perform the required analysis?
2. b. Which assumptions required by the F-test are likely to be violated in this problem? Explain.
3. c. Use the Kruskai-Wallis H-test to determine whether the salary distributions differ among the three cities. Specify your null and alternative hypotheses and state your conclusions in the context of the problem. Use α = .05.
4. d. What assumptions are necessary to ensure the validity of the nonparametric test in part c?