$($For Part $($a$)$ to Part $($d$))$: There are two machines, machine A and machine B$,$ with parameters as shown below. $(16$ points$)$

$\backslash$table$[[$Parameter $($in minutes$),$Machine A$,$Machine B$],[$Process time,$22,19],[$STDEV of process time,$1\mathrm{.}5,3],[$Mean time to failure,$1451,1432],[$Mean time to repair,$90,85],[$STDEV of mean time to repair,$13,50]]$

a$)$ What are the availabilities of machine A and machine $B,$ respectively? $(4)$

A$.95\mathrm{.}32\%,94\mathrm{.}40\%$

C$.94\mathrm{.}16\%,94\mathrm{.}40\%$

B$.94\mathrm{.}40\%,94\mathrm{.}16\%$

D$.94\mathrm{.}40\%,95\mathrm{.}32\%$

b$)$ Find the squared coefficient of effective variability of machine A and machine $B,$ respectively $(4)$

A$.0\mathrm{.}2343,0\mathrm{.}2555$

C$.0\mathrm{.}3434,0\mathrm{.}2343$

B$.0\mathrm{.}2343,0\mathrm{.}3434$

D$.0\mathrm{.}2555,0\mathrm{.}2343$