In painting an automobile, the thickness of the color coat has a lower specification limit of 0.80

Question:

In painting an automobile, the thickness of the color coat has a lower specification limit of 0.80 mil and an upper specification limit of 1.20 mils. Find the Cp and Cpk capability indexes if
(a) The process mean is 1.00 mil and the process standard deviation is 0.05 mil; and
(b) The process mean is .90 mil and the process standard deviation is 0.05 mil.