ID PERT$2$

Using PERT Julie was able to determine that the expected project completion time for the construction of a pleasure yacht is $21$ months and the project variance is $4.$ What is the due date that yields a $95\%$ of completion?

$24\mathrm{.}29$

$21\mathrm{.}84$

$27\mathrm{.}34$

$22\mathrm{.}53$