The city manager of a large midwestern city was negotiating with the three unions that represented the police, firefighters, and building inspectors over the salaries for these groups of employees. The three unions claimed that the starting salaries were substantially different among the three groups, whereas in most cities there was not a significant difference in starting salaries among the three groups. To obtain information on starting salaries across the nation, the city man­ager decided to randomly select one city in each of eight geographical regions. The starting yearly salaries ( in thousands of dollars) were obtained for each of the three groups in each of the eight regions. The data appear here.

a. Write a model for this study, identifying all the terms in the model.
b. Do the data suggest a difference in mean starting salaries for the three groups of employees? Use α = .05.
c. Give the level of significance for your test.
d. Which pairs of jobs types have significantly different starting salaries?

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Region Police Firefighters 39 328 36 312 30.8 306 28.7 27.5 30.64 Inspectors 27.9 278 265 268 264 268 25.3 25.9 26.68 Region mean 307313 29.6 29.5 29. 29 27.5 27.1 29.25 6 Mean 32.3 33.2 308 305 30 30.2 28.4 27.9 30.42