Consider the following PERT network$/$ CPM network with estimated times in weeks. activity A $,$ B$,$C$,$D$,$ Variance$-1\mathrm{.}1,0\mathrm{.}5,1\mathrm{.}2,0\mathrm{.}8,$ activity$-$ E$,$F$,$G$,$H variance$-0\mathrm{.}3,0\mathrm{.}6,0\mathrm{.}6,0\mathrm{.}6,1\mathrm{.}0$