Managing for Quality and Performance Excellence 9th Edition by James Evans,William Lindsay

Exercise 49

Auditors at the Numeros Verdes Partners, P.S.C. took a sample of 200 accounts payable bills, as shown in the table found in the Excel worksheet Prob. 6-2 in the Excel workbook C06Data.xlsx.
a. Find the proportion of the accounts payable in the sample that are classified as overdue by using the Excel COUNTIF function.
b. If an auditor takes a random sample of only 10 accounts from this population, assuming that they follow a binomial distribution, what is the probability that: (i) exactly 5 bills will be overdue? (ii) 4 or fewer bills will be overdue? (iii) 6 or more bills will be overdue? Use the binomial probability distribution formula and verify your result using Excel Binomial spreadsheet template.