A company manufacturing oil seals wants to establish a? and R control charts on the process. There are 40 preliminary samples of size 10 on the internal diameter of the seal. The summary data (in mm) are as follows, #312 = 1280 and R = 4.35 (a) What are the three-sigma control limits for J? and R? (b) Assume that the 40 preliminary samples plot in control on both charts. Estimate the process standard deviation. (c) If the process mean shifts by +5 units (mean increases by 5 units), what is the probability of not detecting this shift on the first subsequent sample