A machine shop owner wishes to monitor the diameter of an engine boring operation where the piston bore should be 4.25”. He obtains 8 samples of 5 and records the following data. Calculate the control limits for X bar and R charts, plot the charts and indicate if the process is in control.
Sample #
1 2 3 4 5 6 7 8
5.1 4.7 4.3 4.6 4.6 4.8 4.9 4.3
4.4 4.5 4.6 4.4 4.3 4.3 5.1 4.8
4.7 4.9 4.4 5 4.7 4.8 4.5 5
4.9 5.1 4.6 4.9 5 5 4.6 4.7
4.9 5.2 4.9 4.7 4.7 4.3 4.7 5.2