Question: Consider the example of Applied Machines presented in Problem. Based on the estimate of the probability that a machine is sent back for rework computed from the 20 months of data, determine the following:
a. If the company produces 35 machines in one particular month, how many, on average, require rework?
b. Out of 100 machines produced, what is the probability that more than 20 percent of them require rework? (Use the normal approximation to the binomial for your calculations.
Problem: Applied Machines produces large test equipment for integrated circuits. The machines are made to order, so the production rate varies from month to month. Before shipping, each machine is subject to extensive testing. Based on the tests the machine is either passed or sent back for rework. During the past 20 months the firm has had to rework the following numbers of machines:
Determine if the process was in control for the 20-month period using a standardized version of the p chart. Assume three-sigma limits for the control chart.