A study reported in the Journal of Occupational and Organizational Psychology (Dec. 1992) investigated the relationship of employment status to mental health. A sample of 49 unemployed men was given a mental health examination using the General Health Questionnaire (GHQ).The GHQ is a widely recognized measure of present mental health, with lower values indicating better mental health. The mean and standard deviation of the GHQ scores were i = 10.94 and s = 5.10, respectively.

a. Specify the appropriate null and alternative hypotheses if we wish to test the research hypothesis that the mean GHQ score for all unemployed men exceeds 10. Is the test one-tailed or two-tailed? Why?

b. If we specify a = .05, what is the appropriate rejection region for this test?

c. Conduct the test, and state your conclusion clearly in the language of this exercise.