Process Capability Problem

A metal fabricator process connecting rods with an outer diameter that has a $1+/-\mathrm{.}01$ inch specification. A machine operator takes several sample measurements over time and determines that the best estimate of the outer diameter for the mean is $1\mathrm{.}002$ inches with a standard deviation of $\mathrm{.}003$ inch.

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a$)$ Calculate the process capability index. $($Cpk$)$

b$)$ What does this mean in context of this situation?

c$)$ What $\%$ of the population of measurements are outside of specifications?