In this example, the capability index C pk is computed for the amplification data in AMPS. To examine the accuracy of this estimate, the following statements calculate a 90% confidence interval for C ...

it follows that an estimate of CPU is 1.7 / 3 = 0.57, and an estimate of CPL is 1.8 / 3 = 0.6. Thus, except for a factor of three, you can estimate CPU and CPL from the points of intersection between ...