A process is in statistical control with $\frac{?}{\text{b}\text{a}\text{r}}(\stackrel{}{x})=199$ and

$\frac{?}{\text{b}\text{a}\text{r}}(R)=3\mathrm{.}5.$ The control chart uses a sample size of

$n=4.$ Specifications are at $200+-8.$ The quality char$-$

acteristic is normally distributed.

$($a$)$ Estimate the potential capability of the process.

$($b$)$ Estimate the actual process capability.

$($c$)$ How much improvement could be made in

process performance if the mean could be cen$-$

tered at the nominal value?