Question: A researcher randomly sampled 30 graduates of an MBA program and recorded data concerning their starting salaries. Of primary interest to the researcher was the effect of gender on starting salaries. The summary results are given below:

Female MBA Graduates: Sample mean = $48266, Population standard deviation = 13500, Sample size = 18

Male MBA Graduates: Sample mean = $55000, Population standard deviation = 12000, Sample size = 12

Assuming that the populations are normally distributed, is there evidence of a difference in the average starting salary of the male MBA graduates and the female MBA graduates? Use a 0.05 level of significance.