1. Control charts for , R, and s are to be maintained for the threshold voltage of short-channel MOSFETs using sample sizes of n = 10. It is known that the process is normally distributed with µ = 0.75 V and σ = 0.10 V. Find the centerline and control limits for each of these control charts.
2. Repeat the previous problem assuming that µ and σ are unknown and that we have collected 50 observations of sample size 10. These samples yielded a grand average of 0.734 V, an average si of 0.125 V, and an average Ri of 0.365 V.