$\backslash$table$[[$Activity$,$Optimistic,Most Probable,Pessimistic$],[$A$,6,7\mathrm{.}0,8],[$B$,7,8\mathrm{.}0,9],[$C$,7,7\mathrm{.}5,10\mathrm{.}5],[$D$,7,9\mathrm{.}0,10],[$E$,6,7\mathrm{.}0,9],[$F$,5,6\mathrm{.}0,7]]$

$($a$)$ Compute the expected activity completion times and the variance for each activity. $($Round your answers to two decimal places.$)$

$\backslash$table$[[$Activity$,\backslash$table$[[$Expected$],[$Times$]],$Variance$],[$A$,,,,$