A random sample of size n = 36 is taken from a population with mean μ = 150 and standard deviation σ = 42.

a. Construct the centerline and the upper and lower control limits for the chart.

b. Suppose five m ore sam ples of size 36 w ere drawn, producing th e following sam ple m eans: 1 3 3 , 1 4 2 , 150, 165, and 169. Plot these values on the chart.

c. Are any points outside the control limits? Does it appear that the process is under control? Explain. L056