Question

Using PERT, Adam Munson was able to determine that the expected project completion time for the construction of a pleasure yacht is 15 months, and the project variance is 4, the probability that the project will be completed in 16 months is _ (Round to one decimal place)

Answer 1

approximately 0.7

Step-by-step explanation:

Pert Analysis is used to compute/sum up the various variances of a project along its critical path

using PERT

The mean value of project ( estimated project time ) = 15

project variance б = 4

standard deviation =
`\sqrt{}` б = 2

probability that project will be completed on or before 16 months

= P ( X ≤ 16 )

this means Z ≤
`(X - 15)/(2)` where X = 16

= Z ≤ 1

using the the normal distribution appendix for the Z value the probability of completing the project in 16 months would approximately be 0.7

Answer 2

The probability that the project will finish in 16 months is 0.7.

Step-by-step explanation:

From the data the mean time is given as
`\mu=15`

The variance is given as
`\sigma^2=4\\`

So the standard deviation is
`\sigma=2\\`

Now the X is given as 16 so

Calculating the z score as

`z=(x-\mu)/(\sigma)\\z=(16-15)/(2)\\z=(1)/(2)=0.5`

So for the z score of 0.5 the probability is given in Excel as

=NORMSDIST(0.5)

=0.69 ≈0.7

So the probability that the project will finish in 16 months is 0.7.