Hello! I'm having trouble with this practice problem. I'm not too sure what I'm doing wrong. Thank you for your help!

Office Automation, Inc., developed a proposal for introducing a new computerized office system that will standardize the electronic archiving of invoices for a particular company. Contained in the proposal is a list of activities that must be accomplished to complete the new office system project. Use the following relevant information about the activities. Time (weeks) Activity A B C D E Description Order equipment Install equipment Set up training lab Conduct training course Test system (a) Develop a project network. (Submit a file with a maximum size of 1 MB.) Choose File No file chosen This answer has not been graded yet. F Plan needs Immediate Predecessor A B A D C, E Normal Crash Normal Crash 10 8 10 7 10 3 8 160 7 6 00 8 Cost ($1000s) 3 30 120 100 40 50 60 70 150 160 50 75 (b) Develop an activity schedule. Activity A B D E F Earliest Start Latest Start Earliest Finish What is the expected project completion time (in weeks)? weeks Latest Finish (c) What are the critical activities? (Enter your answers as a comma-separated list.) Slack (d) Assume that the company wants to complete the project in six months or 26 weeks. What is the amount of crash time (in weeks) for each activity that minimizes cost? (A, B, C, D, E) = (e) Develop an activity schedule for the crashed project. Earliest Start Activity A B D E F Latest Start Earliest Finish Latest Finish Slack (f) What added project cost (in thousands of dollars) is required to meet the six-month completion time? thousands of dollars