A controlled process exhibits an overall average of $x-$bar$-$bar $=2\mathrm{.}5$ and $r-$bar $=0\mathrm{.}42.$ Samples of six items were taken from the process.

a$.$ What is the mean process capability $($round to $3$ decimals$)?$

$UC{L}_{x\frac{-}{b}ar}=$

$LC{L}_{x-\text{b}\text{a}\text{r}}=$