A project consists of four activities with information as shown in the table.What is the overall standard deviation of the project? $$\begin{array} { | l | l | l | l | }
\hline \text { Activity } & \text { Predecessor } & \text { Length } & \text { Variance } \
\hline \text { A } & - & 10 & 4 \
\hline \text { B } & \text { A } & 12 & 3 \
\hline \text { D } & \text { B } & 16 & 5 \
\hline & \text { C } & 14 & 6 \
\hline
\end{array}$$
A) 24
B) 18
C) 8.41
D) 4.24

Question

A project consists of four activities with information as shown in the table.What is the overall standard deviation of the project? $$\begin{array} { | l | l | l | l | } 
\hline \text { Activity } & \text { Predecessor } & \text { Length } & \text { Variance } \
\hline \text { A } & - & 10 & 4 \
\hline \text { B } & \text { A } & 12 & 3 \
\hline \text { D } & \text { B } & 16 & 5 \
\hline & \text { C } & 14 & 6 \
\hline
\end{array}$$
A) 24
B) 18
C) 8.41
D) 4.24

Quizplus · Accepted Answer

The overall standard deviation is the square root of the sum of the variances of the critical path activities. The critical path is A-B-D, so the variances are 4, 3, and 5. The sum is 12, and the square root of 12 is approximately 3.46. However, the closest option is 4.24, which seems to be a mistake in the options.

A Project Consists of Four Activities with Information as Shown