Explain step by step $8\mathrm{.}12.$ Suppose that $20$ of the parts manufactured by the processes in Exercise $8\mathrm{.}11$ were assembled so that their dimensions were additive; that is$,$

x$=$x$\_1+$x$\_2++$x$\_20$

Specifications on x are $2000\backslash$pm $200.$ Would you prefer to produce the parts using process A or process B $?$ Why? Do the capability ratios computed in Exercise $8\mathrm{.}11$ provide any guidance for process selection?