Task time estimates for the modification of an assembly line at jim goodale's carbondale, illinois, factory are as follows: activity | time (in hours) | immediate predecessors a | 6.0 | -- b | 7.2 | -- c | 5.0 | a d | 6.0 | b, c e | 5.0 | b, c f | 7.7 | d g | 4.0 | e, f (a) draw the project network using aon. (b) identify the critical path. (c) what is the expected project length? (d) draw a gantt chart for the project.