A sample of143corporate managers and another sample of142college professors produced mean job-related stress scores of7.18for the managers and7.05for the professors. Suppose that the standard deviations of the stress scores are1.32for the managers and1.90for the professors. The null hypothesis is that the mean stress scores are the same for corporate managers and college professors, while the alternative hypothesis is that the mean stress score for managers is different from the mean stress score for professors.

Derive the corresponding 90% confidence interval for the difference between the mean stress scores for all corporate managers and college professors, rounded to three decimal places.

The lower limit is .

The upper limit is .

The significance level for the test is 1%. What are the critical values ofz?

What is thep-value for this test, rounded to four decimal places?