A company manufactures an electrical cooling fan. It is concerned about the performance of its production process. Over the past 10 days, it has collected samples of performance of the process. There were 8 observations in each sample. Measurements
Day 1 2 3 4 5 6 7 8 9 10
Mean 12.50 12.45 12.55 12.50 12.45 12.60 12.48 12.46 12.56 12.48
Range 1.1 1.2 0.9 0.8 0.9 1.0 1.4 1.1 0.9 . 0.8
Additional information that you might need is provided on the next page.
a) Establish the appropriate control limits for the control chart(s) that would be used to determine if the process in control?
b) Plot the necessary control charts. The appropriate control charts are to be created to receive full credit on this part. Graph paper is on the second page following if you want to use it (Please send me the excel sheet)
c) Based on this data, would you conclude that the process is in control or is there a problem with the process? Explain.