A project has 3 independent stages that must be completed in sequence.The time to complete each stage is a random variable.The standard deviations of the completion times for the stages are σ1 = 8,σ2 = 10,σ3 = 18.The standard deviation of the overall project completion time is
A)12.00
B)36.00
C)22.09
D)25.24

Question

Quizplus · Accepted Answer

The standard deviation of the overall project completion time is the square root of the sum of the variances of the stages: √(σ1² + σ2² + σ3²) = √(8² + 10² + 18²) = √(64 + 100 + 324) = √488 ≈ 22.09.

A Project Has 3 Independent Stages That Must Be Completed