Motorola used the normal distribution to determine the probability of defects and the number of defects expected in a production process. Assume a production process produces items with a mean weight of 11 ounces.

a. The process standard deviation is 0.12 , and the process control is set at plus or minus standard deviations . Units with weights less than 10.7 or greater than 11.3 ounces will be classified as defects. What is the probability of a defect (to 4 decimals)?

In a production run of 1000 parts, how many defects would be found (to the nearest whole number)?

b. Through process design improvements, the process standard deviation can be reduced to .10 . Assume the process control remains the same, with weights less than 10.7 or greater than 11.3 ounces being classified as defects. What is the probability of a defect (to 4 decimals)?

In a production run of 1000 parts, how many defects would be found (to the nearest whole number)?

c. What is the advantage of reducing process variation, thereby causing a problem limits to be at a greater number of standard deviations from the mean?