Use the following problem statement to answer questions $26-29.$

The NF homebuilding company plans to build a new shopping center. A consultant for the company has constructed a project network and estimated activity times, in weeks. The consultant found the following critical path: A $->$ C $->$ D$.$ The expected activity times of A$,$ C and D are $11,8,$ and $5$ weeks. The variances of A$,$ C and D are $4,2,$ and $1.$ Round to four decimal places. $[$Note: z $=($X$-$t$)/\backslash$sigma $]$