I need help. I know my LF, LS, and Slack Formulas are wrong. I need to answer questions A-E.

OSHA ordered Mills River Textile company to buy new machinery for a safe environment. OSHA gave 35 weeks to make the changes to the manufacturer. There will a fee of $300,000 if the changes were not made by then. Following is a list of activities, their precedence relationships, and probabilistic time estimates for this project: For this project determine the following: a. Draw the network diagram. Determine ES, LS, EF and LF for each activity. b. What is the variance for each activity? c. What is the critical path and time? d. What is the activity variance along the critical path? e. The probability that the firm will be fined $300,000