The process capability index $(\frac{C_p}{C_{pk}})$

Is the mean divided by the square of the standard deviation $($variance$)$

Should be $<mn\; id="EditorElement\_718443">1</mn>$ for a capable process

Is the ratio of the range of values allowed divided by the range of values produced

Is the ratio of the range of values produced divided by the range of values allowed

Defines the mean and standard deviation of the process

Should be $=0\mathrm{.}5$ for a capable process