An EWMA chart with L=3 is used to monitor individual observations in a process. The process mean and standard deviation are 170 and 10, respectively. (a) If the upper control limit for the steady state is 180. Please calculate . What is the steady state low control limit? (5 points) (b) If increasing L without changing , how does it affect ARL0 and ARL1 ? (just simply answer (i) increase, (ii) decrease, (iii) no change)