Mrs. Toguchi wants to determine if politicians tend to have higher salaries, on average, than first responders (specifically emergency medical technicians, EMTs). Independent random samples from each of these two professions were selected and their salaries were recorded. The data are summarized below.

Politicians EMTs

Mean $61,234 $54,529

Standard Deviation $7,524 $5,551

n 50 100

a). The distribution of salary in each group is skewed right. The use of two-sample t procedures is still justified. Why?

b). Construct and interpret a 99% confidence interval for the difference in the true mean salaries for politicians and EMTs.