Do male and female servers work the same number of hours? A sample of 25 female servers worked an average of 26 hours per week, with a standard deviation of 2. A sample of 11 male servers worked an average of 23 hours per week, with a standard deviation of 4. Let μ 1 and μ 2 represent the typical number of hours worked by all female and male servers, respectively. Construct a 90% confidence interval for μ 1 − μ 2 , assuming normal populations with unequal variances.