A certain process is under statistical control and has a mean value of = 130 and

Question:

A certain process is under statistical control and has a mean value of μ = 130 and a standard deviation of σ = 8. The specifications for this process are USL = 150, LSL = 100.
a. Calculate Cp and Cpk.
b. Which of these indices is a better measure of process capability? Why?
c. Assuming a normal distribution, what percent of the product can be expected to fall outside the specifications?