Managing for Quality and Performance Excellence 10th Edition by James Evans ,William Lindsay

Exercise 61

Note: Data sets for many problems in this chapter are available in the Excel workbook C09Data.xlsx on the Student Companion Site. Click the appropriate worksheet tab as noted in the problem ( e.g. Prob. 9-12, etc.) to access the data. We also recommend using the ASQ Learn about Quality Excel templates noted in this chapter to facilitate your solutions to appropriate problems.
During one month, CienesInvCo (CIC) processed 25,000 invoices for Alpha Corp, 23,000 for Beta Corp, and 8,000 for Gamma Corp. Of these, 205 of the Alpha, 175 of the Beta, and 103 of the Gamma invoices had to be reprocessed for errors. What is the overall defect rate and the sigma level for all of the combined batches? For each individual batch?