Activity Description Optimistic $($a$)$ Most Probable $($m$)$ Pessimistic $($b$)$

A Plan event $234$

B Select location $2\mathrm{.}526$

C Decide on speakers & vendors $444$

D Prepare & mail brochures $246$

E Update web site $1\mathrm{.}52\mathrm{.}53\mathrm{.}5$

F Final check with speakers & vendors $3\mathrm{.}544\mathrm{.}5$

G Registration & hotel reservations $336$

H Finalize last$-$minute details $255$

Suppose the Critical Path is A$-$C$-$D$-$G$-$H$,$ the estimated probability that the project will be completed between $18$ and $20$ weeks is $($round z values to $2$ decimal places$)$

$67\mathrm{.}30\%$

$32\mathrm{.}70\%$

$33\mathrm{.}65\%$

$16\mathrm{.}35\%$