Use the Values in the Table to Calculate Activity Durations

Use the values in the table to calculate activity durations and variances for the project.What is the project deadline such that there is a 75% chance it is completed on time?
$\begin{array}{|l|l|l|l|}\hline \text { Activity } & \text { Activity time } & \begin{array}{l}\text { Standard } \\\text { deviation }\end{array} & \text { Predecessor } \\\hline \mathrm{A} & 12 & 3 & \\\hline \mathrm{B} & 8 & 2 & \mathrm{~A} \\\hline \mathrm{C} & 9 & 1 & \mathrm{~A} \\\hline \mathrm{D} & 5 & 1 & \mathrm{~B} \\\hline \mathrm{E} & 12 & 0 & \mathrm{~B} \\\hline \mathrm{F} & 10 & 0 & \mathrm{C} \\\hline \mathrm{G} & 7 & 2 & \mathrm{C} \\\hline \mathrm{H} & 9 & 3 & \mathrm{E}, \mathrm{G} \\\hline \mathrm{I} & 15 & 2 & \mathrm{D}, \mathrm{G} \\\hline \mathrm{T} & 8 & 2 & \mathrm{H} \\\hline \mathrm{K} & 11 & 3 & \mathrm{I} \\\hline \mathrm{L} & 7 & 2 & \mathrm{~J}, \mathrm{~K} \\\hline\end{array}$