Tasks A, B, and C must be completed in series to complete a project. The three time estimates (a, m, and b) for each task in weeks are A:8,11, and 14weeks; B:7,10, and 19weeks; and C:10,19, and 22weeks. For each task, calculate (a) the expected time te and (b) the standard deviation . What is the (c) expected time Te and (d) the standard deviation T for the complete project? What is the probability of completing the project in (e) 40weeks? (f) 46weeks?

NEED HELP HOW TO CALCULATE THE STANDARD DEVIATION