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

Exercise 65

Note: Data for many of the problems in this chapter can be found in the Excel workbook C08Data.xlsx on the Student Companion Site. Click on the appropriate worksheet tab as noted in the problem (e.g., Prob. 8-6, etc.) to access the data.
Palma State Bank is investigating the processing time for loan applications. Samples were taken for 25 random days from 5 branches. These data can be found in the worksheet Prob. 8-23 in the C08Data.xlsx file on the Student Companion Site for this chapter.
a. Using Microsoft Excel ® or similar software with statistical capability, construct a histogram for these 125 individual readings.
b. Construct a run chart for the sample means.
c. Interpret what the data show. Does the process appear to be in control?