The estimated times and immediate predecessors for the activities in a project at Howard Umrah's retinal scanning company are given in the following table. Assume that the activity times are independent. This exercise contains only parts a,b,c, and d. a) Based on the activity time estimates; the expected times and variance for each of the activities are (round your response to two decimal places): a) Based on the activity time estimates, the expected times and variance for each of the activities are (round your response to two decimal places): b) The expected completion time of the project = weeks (round your response to two decimal places). c) The project variance of completion time = weeks (round your response to ( wo decimal places) d) If the time to complete the project is normally distributed, then the probability that the proj:ct will be finished in 21 weeks or less = (enter as a probability and round your response to two decimal places)