Question 1. Samples of n = 4 items are taken from a process atregular intervals. A normally distributed quality characteristic ismeasured and x-bar and s values are calculated at each sample.After 50 subgroups have been analyzed, we have
? x?i = 1,000 and ?si = 72
(A) Compute the control limit for the x and s control charts
(B)Assume that all points on both charts plot within the controllimits. What are the natural tolerance limits of the process?
(C) if the specifications limits are 19 + 4.0 what are yourconclusions regarding the ability of the process to produce itemsconforming to specifications?
(D) Assuming that if an item exceeds the upper specificationlimit it can be reworked, and if it is below the lowerspecification limit it must be scrapped, what percentage scrap andrework is the process now producing?
(E) If the process were centered at u = 19.0, what would be theeffect on percentage scrap and rework?
