The reasons given by workers for quitting their jobs generally fall into one of two categories: (1) worker quits to seek or take a different job, or (2) worker quits to withdraw from the labor force. Economic theory suggests that wages and quit rates are related. The table on page 528 listsauitrates(auitsner100emnlovees)andtheaverape hourly wage in a sample of 15 manufacturing industries.
A MINlTAB printout of the simple linear regression of quit rate y on average wage x is shown on p. 528.

a. Do the data present sufficient evidence to conclude that average hourly wage rate contributes useful information for the prediction of quit rates? What does your model suggest about the relationship between qu~t rates and wages?

b. A 95% prediction interval for the quit rate in an industry with an average hourly wage of $9.00 is given at the bottom of the MINITAB printout. Interpret the result.

c. A 95% confidence interval for the mean quit rate for industries with an average hourly wage of $9.00 is also shown on the printout. Interpret this result.