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

Exercise 74

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.
Constant Hope Hospital wants to set up a control chart for the time required to perform a critical step in gall bladder surgery. Use the data, consisting of 25 samples of size 4 found in the worksheet Prob. 8-33 in the C08Data.xlsx file to construct
-and s -charts. What conclusions do you reach concerning the state of the process? Is it under control? Why or why not?