According to an Experiential Education Survey published at JobWeb.com, the average hourly wage of a college student working as a co-op is $15.64 an hour and the average hourly wage of an intern is $15.44. Assume that such wages are normally distributed in the population and that the population variances are equal. Suppose these figures were actually obtained from the data below.

a. Use these data and α = .10 to test to determine if there is a significant difference in the mean hourly wage of a college co-op student and the mean hourly wage of an intern.

b. Using these same data, construct a 90% confidence interval to estimate the difference in the population mean hourly wages of co-ops and interns.

Co-op Students Interns

$15.34 ...........$15.10

14.75 ...........14.45

15.88 ...........16.21

16.92 ...........14.91

16.84 ...........13.80

17.37 ...........16.02

14.05 ...........16.25

15.41 ...........15.89

16.74 ...........13.99

14.55 ...........16.48

15.25 ...........15.75

14.64 ...........16.42