Here are the precedence requirements, normal and crash activity times, and normal and crash costs for a project: Required time (weeks) Activity Crash Expediting Cost/week ($) Preceding activity Normal None 3 3,000 2,000 2,000 2,000 4,500 2,500 2 B, C D, E 2 Under normal activity time, the critical path is and the project completion time is weekS The slack times of activity B, C, and D under normal activity time are and respectively. In order to shorten the entire project by 6 weeks, we should first shorten activity weeks and then activity weeks with a total expediting cost of dollars