Answer:
On average, the project takes 4 weeks to complete.
Step-by-step explanation:
We have these following probabilities:
25% probability that the activity takes 2 weeks.
50% probability that the activity takes 4 weeks.
25% probability that the activity takes 6 weeks.
How long does the project now take to complete (on average)
We multiply each duration by it's probability.
0.25*2 + 0.5*4 + 0.25*6 = 4
On average, the project takes 4 weeks to complete.