The following table shows the average hourly wage rates for day-care centers from the Northeast and Midwest regions of the United States based on two random samples:

Northeast Midwest Sample mean $9.60 $8.60 Sample standard deviation $1.25 $1.20 Sample size 26 31

a. Perform a hypothesis test using a = 0.05 to determine if the average hourly wage for day-care workers in the Northeast is $0.50 per hour higher than day-care workers in the Midwest. Assume the population variances for wage rates in each region are equal.

b. Approximate the p-value using Table 5 in Appendix A and interpret the results.

c. Determine the precise p-value using Excel.

d. Verify your results using PHStat.

e. What assumptions need to be made in order to perform this procedure?

AppendixLO1