Managing Supply Chain and Operations 1st Edition by Thomas Foster ,Scott Sampson,Cynthia Wallin,Scott Webb

Exercise 20

Four samples (k = 4) arc taken from a process, with each sample consisting of five observations (n = 5). The sampled items are subjected to a stress test, and the amount of pressure, measured in pounds per square inch, required to crack each item was computed. The results are as follows: Develop an R chart to determine if the dispersion is stable or not.