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

Exercise 48

Note: Data sets for many problems in this chapter are available in the Excel workbook C06Data.xlsx on the Student Companion Site. Click on the appropriate worksheet tab as noted in the problem (e.g., Prob. 6-1) to access the data. In addition, the spreadsheet templates illustrated in the chapter are also available to aid in solving many of these problems.
Tessler Electric utility requires service operators to answer telephone calls from customers in an average time of 0.1 minute or less. A sample of 25 actual operator times was drawn, and the results are given in the following table. In addition, operators are expected to determine customer needs and either respond to them or refer the customer to the proper department within 0.5 minute. Another sample of 25 times was taken for this job component and is also given in the table. If these variables can be considered to be independent, are the average times taken to perform each component statistically different from the standards?