Task X has a most likely duration of 10 days,a best-case duration of 8 days,and a worst-case duration of 15 days.What is the probability that it will be completed in 12 days or less?
A)0 percent
B)95.7 percent
C)90.1 percent
D)75.3 percent

Question

Quizplus · Accepted Answer

To find the probability that Task X will be completed in 12 days or less, we need to use the three-point estimate to calculate the expected duration (ED) and standard deviation (SD):
ED = (10+4(8)+15)/6 = 10.5 days
SD = (15-8)/6 = 1.17 days

Then we can use the normal distribution to calculate the probability:
Z = (12-10.5)/1.17 = 1.28
From the standard normal distribution table, the probability of Z less than or equal to 1.28 is about 0.9015.
Therefore, the probability that Task X will be completed in 12 days or less is about 90.15%, which is closest to choice C (90.1 percent).

Task X Has a Most Likely Duration of 10 Days,a