The Bureau of Labor Statistics publishes data on weekly earnings of full-time wage and salary workers in Employment and Earnings. Male and female workers were paired according to occupation and experience. Their weekly earnings, in dollars, are provided on the WeissStats CD. Use the technology of your choice to do the following.
a. Apply the paired t-test to decide, at the 5% significance level, whether the data provide sufficient evidence to conclude that, on average, the weekly earnings of male full-time wage and salary workers exceed those of women.
b. Find and interpret a 90% confidence interval for the difference between the mean weekly earnings of male and female full-time wage and salary workers. Use the paired t-interval procedure.
c. Obtain a normal probability plot, boxplot, and stem-and-leaf diagram of the paired differences.
d. Based on your results in part (c), are your procedures in parts (a) and (b) justified? Explain your answer.