Ten samples of size n = 8 have been collected from a process in statistical control, and the dimension of interest has been measured for each part. The calculated values of for each sample are (mm) 9.22, 9.15, 9.20, 9.28, 9.19, 9.12, 9.20, 9.24, 9.17, and 9.23. The values of R are (mm) 0.24, 0.17, 0.30, 0.26, 0.26, 0.19, 0.21, 0.32, 0.21, and 0.23, respectively.
(a) Determine the values of the center, LCL, and UCL for the x and R charts.
(b) Construct the control charts and plot the sample data on the charts.