a$.$ Draw the sample mean and sample range control charts for this operation. Is the process in control? Explain why.

b$.$ The eight sample contains the following values: $0\mathrm{.}1229,0\mathrm{.}1231,0\mathrm{.}1271,0\mathrm{.}1243,0\mathrm{.}1254,$ and $0\mathrm{.}1236.$ Using the control charts from part a$,$ is the process in control? Explain why.

c$.$ The specification range is between $0\mathrm{.}1220$ and $0\mathrm{.}1270$ inches. Calculate the Cp and Cpk

ratios. Is the milling process capable? Explain why.

d$.$ What proportion of rings will not meet the design specification?