Problem 4: A manufacturing process produces engines. The average number of defective light bulbs in a sample of 500 is known to be 2.0 . a) Suppose the manufacturer considers the upper control limit to be two standard deviations above the mean. How many defective engines in a sample of 1000 would that be? b) Suppose the manufacturer considers the lower control limit to be two standard deviations below the mean. How many defective engines in a sample of 1000 would that be