Task time estimates for the modification of an assembly line at Jim Goodale's Carbondale, Illinois, factory are as follows:

$\backslash$table$[[$Activity$,\backslash$table$[[$Time$],[($in hours$)]],$Immediate Predecessor$($s$)],[$A$,5\mathrm{.}0,-],[$B$,7\mathrm{.}5,-],[$C$,6\mathrm{.}0,$A$],[$D$,6\mathrm{.}0,$B$,$ C$],[$E$,5\mathrm{.}0,$B$,$ C$],[$F$,7\mathrm{.}5,$D$],[$G$,4\mathrm{.}0,$E$,$ F$]]$