Question

You have determined the critical path in a CPM analysis. You would like to determine the probability of completing the project is a desired period of time. One of the activities on the critical path has an optimistic time of 5 minutes, a most likely time of 6, and a pessimistic time of 17. What is the variance estimate of this activity?

Answer 1

Answer:

The variance estimate of this activity is 4.

Step-by-step explanation:

Given information: One of the activities on the critical path has

Optimistic time = 5 minutes

Most likely time = 6 minutes

Pessimistic time = 17 minutes

The variance estimate of a activity is

$\sigma ^2=(\frac{t_p-t_o}{6})^2$

where, $t_p$ is pessimistic time of that activity and  $t_o$ is optimistic time of that activity.

The variance estimate of the given activity is

$\sigma ^2=(\frac{17-5}{6})^2$

$\sigma ^2=(\frac{12}{6})^2$

$\sigma ^2=2^2$

$\sigma ^2=4$

Therefore the variance estimate of this activity is 4.