1. Refer to Exercise 3 in Section 10.2.

a. Delete any samples necessary to bring the process variation under control. (You did this already if you did Exercise 3 in Section 10.2.)

b. Use R to estimate σX (σX is the difference between X and the 1σ control limit on an X chart).

c. Construct a CUSUM chart, using X for the target mean µ, and the estimate of σX found in part

(b) for the standard deviation. Use the values k = 0.5 and h = 4.

d. Is the process mean in control? If not, when is it first detected to be out of control?

e. Construct an X chart, and use the Western Electric rules to determine whether the process mean is in control. (You did this already if you did Exercise 3 in Section 10.2.) Do the Western Electric rules give the same results as the CUSUM chart? If not, how are they different?