Control Charts for the Process Mean For the processes

described in Exercises $4-5,$ determine the upper and

lower control limits for an $\stackrel{}{x}$ chart. Construct the

control chart and explain how it can be used.

The sample means were calculated for $30$ samples

of size $n=10$ for a process that was judged to be in

control. The means of the $30\stackrel{}{x}-$values and the standard

deviation of the combined $300$ measurements were

$\frac{?}{\text{b}\text{a}\text{r}}(\stackrel{}{x})=20\mathrm{.}74$ and $s=\mathrm{.}87,$ respectively.