3. a) Define what is mean by "Statistical Process Control" and use your own sketch to show a control chart for mean values. Highlight the differences between tolerance limits and control limits. b) Define the control limits for Mean and Range Charts using constants A2, D3 and D4. c) The following Mean and Range data was generated from sample length measurements with a sample sizen 10 on seven batches of steel pins manufactured to: 10.000 +/-0.030 mm !! X bar (mm) 10.014 9.990 9.984 9.980 10.006 10.010 R (mm) 0.120 0.070 0.036 0.066 0.020 0.034 10.050 0.180 (1) Calculate the Grand Mean, Mean Range and the Control Chart Limits. (i) Use graph paper to draw both Control Charts. Indicate where the "out of control" occurs and include the tolerance limits on the Mean Chart. (Use the following constants for n= 10, A2 = 0.308, D3 = 0.223, D4 = 1.777)