Problem 2: A manufacturing process produces copper pipes. The average number of surface cracks per foot of pipe is known to be 36 . a) Suppose the manufacturer considers the upper control limit to be two standard deviations above the mean. How many surface cracks per foot of pipe would that be? b) Suppose the manufacturer considers the lower control limit to be two standard deviations below the mean. How many surface cracks per foot of pipe would that be