10 The following data concern an activity that has to be performed as part of a project:

Expected duration (days) 10 Standard deviation of the duration 2 Expected labor-days 30 Standard deviation of labor-days 3

a. What is the probability that completing the activity on time will require at least a 10%

addition to the expected labor-days?

b. A crew of three workers is assigned to this activity.What is the probability that it will be completed in fewer than 11 days?

State your assumptions for both parts.