Problem:
Mike is preparting the x-bar chart and the R chart for Uncle Ben's 2lb. box rice packaging line. Using the standard sample size of 9 items. Mike found the average range is .02 lbs and the overal process average is 1.98 lbs.
Required:
Question 1) Calculate the upper and lower control limits for the process average chart
Question 2) Calculate the upper and lower control limits for the range chart
Question 3) A random sample of four items as an average weight of 2.2 lbs and a range of 0.03 lb is taken by the quality manager. Based on your calculations explain why these results are not acceptable for both average and range.
Solve the given problem carefully and show all work.