The following data show employees' rates of defective work before and after a change in the wage incentive plan. Before 8 6 9 7 10 8 6 5 8 10 8 After 6 5 8 6 9 8 10 7 5 6 9 8 From the statistical estimate you have calculated, see whether the change lowered the defective units produced. Use the 0.05 level of significance O a. We cannot say O b. None of these O c. The change in incentive system has not lowered the defective units produced O d. The change in incentive system has lowered the defective units produced Next page