15. Using the data in the Excel file, perform a regression analysis to try to predict the time to perform the monthly reconciliation process by the number of defects in each of the processes (accounts payable, accounts receivable and payroll).

16. Using the data in the Excel file, calculate a confidence interval about the mean for the following variables: Accounts payable processing time Accounts receivable processing time Payroll processing time Monthly reconciliation processing time 17. Perform a hypothesis test to test whether the processing time for the first 12 payroll cycles is significantly different from the last 12 payroll cycles. Clearly identify your hypothesis. 18. Calculate the DPMO and related sigma level for the process, assuming a 1.5 sigma shift, for the following data: Opportunities for failure: Timesheet erroneous data, Pay rate error, Payroll processing error Defects: Number of payroll defects per batch: 5 Units: Number of paychecks per batch: 100 19. Calculate the process capability for the accounts payable processing time with the following specifications (15 points): Lower specification limit: two hours Upper specification limit: four hours

AP Defects AR Defects Payroll Defects Monthly Reconciliation (Hours) 10 4 3 81.6 4 3 4 47.8 8 6 70.2 2 10 11.1 4 12 41.3 15 10 48.4 4 76.3 2 39.9 7 69.7 6 99.8 8 73.9 12 35.9 2 58.8 6 8.3 10 50.7 12 90.4 9 31.3 9 41.4 7 54.5 3 58 77.3 61.6 52.6 60.2 4 2 7 10 12 4 2 6 16 12 9 9 7 3 11 12 2 6 2 6 4 2 3 4 5 6 2 3 4 |N| 2 5 3 9 3 5 3 3 3 3 11 6 2 6 A B D E 1 AP Processing Time (Hours) AR Processing Time (Hours) Payroll Process Time (Hours) AR Elapsed Process Time (Hour: Monthly Reconciliation (Hours) 120 24 120 2 81.6 3 2 3 20 96 47.8 70.2; 4 16 72 14 48 5 11.1 18 24 6 41.3 7 12 120 48.4 32 96 8 76.3 17 72 9 39.9 18.5 48 10 69.71 20 24 11 99.8 12 120 12 73.9 15 96 13 35.9 18 72 14 58.8 22 48 8.3 15 30 24 50.7 16 25.5 120 17 90.4 24 96 31.3 18 15 72 19 41.4 14 48 20 54.5 29 24 21 58 24 120 22 77.3 22 96 23 61.61 26 72 24 52.6 18 48 25 60.2 26 4 N 6 2 3 1 8 4 3.5 3.8 4.5 6.2 6 3.3 4.7 5.1 3.4 2.3 3 2.8 4 5 4.4 96 72 48 24 120 96 72 48 24 120 96 72 48 24 120 96 72 48 24 120 96 72 48