The estimated times and immediate predecessors for the activities in a project at Howard Umrah's ret company are given in the following table. Assume that the activity times are independent Time $($weeks $)$ b Time $($weeks $)$ b am Immediate Predecessor $($ s$)$ Activity C Activity A Prede $71013911$ B $51118914$ This exercise contains only parts bd and e a$)$ Based on the activity time estimates $,$ the expected times and variance for each of the activities are $($ response to two decimal places $)$ Activity Expected Time Variance A D