A company uses control charts to monitor the quality of brake shoes produced on the machines. The historical defect rate is 8%. The numbers of defective brake shoes in the last 10 samples produced on Machine 1 are summarized in the table below. Each sample consists of 20 brake shoes. (Note: if ? is needed, let ? = 3).

Sample 1 LU # of 4 5 6 7 8 9 10 defective 1 2 3 brake shoes 2 2 4 4 3 2 1 a) Which type of control chart should be used? b) What is the upper control limit? c) What is the lower control limit? d) Draw the chart. e) Do you think the process is (more likely) in control or not