standard deviation question
ou have been recently assigned to provide an accurate project
schedule for a large construction company.
Your lead engineer has given you the following estimates for several
critical path activities. Your stakeholders want you to commit to a
completion date for these critical path activities. Which of the following
statements are true?
Activity | OPT | PESSI | M.LIKELY | EXPT VAL | STD DEV | SD SQUIRED |
TASK A | 5 | 18 | 10 | 10.5 | 2.17 | 4.69 |
TASK B | 28 | 61 | 40 | 41.5 | 5.50 | 30.25 |
TASK C | 10 | 33 | 18 | 19.17 | 3.83 | 14.69 |
TOTAL | 71.17 | 49.64 | ||||
A. There is approx. 68 percent chance that the project will complete
between 64 days and 78 days.
B. There is approx. 95 percent chance that the project will complete
between 64 days and 78 days.
C. There is approx. 68 percent chance that the project will complete
between 57 days and 85 days.
D. There is approx. 99 percent chance that the project will complete
between 64 days and 78 days.
Answer: A
Please explain why/how the answer is "A"
