(a) Design a symmetrical two-sided cumulative sum control chart to detect a shift of = 1.5 that has in-control average run-length (ARL) equal to 300, Let = 4 and n = 4 . (b) What is the out-of-control ARL for the control chart obtained in (a)? (c) Design a cumulative sum control chart for detecting a shift of -1.7 that has out-of- control ARI 12 . Use and n in (a) If this is not possible explain why. (d) What is the in-control and out-of-control ARL for the control chart obtained in (c)