Given the following task time estimates (HOURS), Task am b Predecessor A 31 40 60 B 15 20 25 C 17 25 41 A D E 15 19 26 A,B 20 25 30 CD 18 24 31 E F G 11 18 22 F a. How long is the project length (round to two decimal places)? [Select ] b. What tasks form the critical path? [Select] , and what is the project variance and standard deviation (round to two decimal places) [Select] c. How much slack is there in activity C? Select ] How much slack in activity D? [Select] d. What is the probability that the project will be completed in 137 hours? [Select] e. How many hours would be required to be 85% sure of completion? [ Select]