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

Exercise 2

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.
Genjeteye, Inc. makes aircraft engines. The mean time to failure has been found to be 100,000 hours and is exponentially distributed.
a. What is the failure rate, ? , per hour?
b. What is the cumulative probability of failure after 10,000 hours or fewer? Between 10,000 and 15,000 hours?
c. If Genjeteye wishes to provide a warranty that no more than 5 percent of the units will fail, how many hours of operation without failure should the company guarantee?