Problem 17-7 Three recent college graduates have formed a partnership and have opened an advertising firm. Their first project consists of activities listed in the following table. Use Table B TIME IN DAYS Activity Predecessor Optimistic Most Likely Pessimistic 15 E, G, I b.What is the probability that the project can be completed in 24 days or less? In 21 days or less? (Round your te and z values to 2 declmal pleces and "Standard devletlon" to 3 declmal places. Round your final answers to 4 declmal places.) 24 days or less 21 days or less c. Suppose it is now the end of the seventh day and that activities A and B have been completed while activity D is 50 percent completed. Time estimates for the completion of activity D are 5. 6, and 7. Activities C and H are ready to begin. Determine the probability of finishing the project by day 24 and the probability of finishing by day 21. (Round your Intermedlate calculetlons to 3 declmal places and final answers to 4 declmal places.) Day 24 Day 21