SOLVED

11) In a PERT network, non-critical activities that have little slack need to be monitored closely: A) because PERT treats all activities as equally important. B) because near-critical paths could become critical paths with small delays in these activities. C) because slack is undesirable and needs to be eliminated. D) because they are causing the entire project to be delayed. E) because they have a high risk of not being completed. 12) Which of the following statements regarding PERT analysis is true? A) Each activity has two estimates of its duration. B) Project variance is the sum of all activity variances. C) Project standard deviation is the sum of all critical activity standard deviations. D) Only critical activities contribute to the project variance. E) The most likely time is equivalent to the expected activity time. 13) A project being analyzed by PERT has 60 activities, 13 of which are on the critical path. If the estimated time along the critical path is 214 days with a project variance of 100, what is the probability that the project will take 224 days or more to complete? A) near zero B) 0.0126 C) 0.1587 D) 0.8413 E) 2.14 14) An activity on a PERT network has these time estimates: optimistic = 2, most likely = 5, and pessimistic = 10. What is its expected activity time? A) 5.00 B) 5.33 C) 5.67 D) 10.67 E) 32.00 15) An activity on a PERT network has these time estimates: optimistic = 1, most likely = 2, and pessimistic = 5. What is its expected activity time? A) 2.00 B) 2.33 C) 2.67 D) 4.67 E) 14.00 16) An activity on a PERT network has these time estimates: optimistic = 2, most likely = 3, and pessimistic = 8. What is its expected activity time and variance? A) 3.67; 1 B) 3.67; 6 C) 4.33; 1 D) 4.33; 6 E) none of the above 17) A local project being analyzed by PERT has 42 activities, 13 of which are on the critical path. If the estimated time along the critical path is 105 days with a project variance of 25, what is the probability that the project will be completed in 95 days or less? A) -0.4 B) 0.0228 C) 0.3444 D) 0.9772 E) 4.2 18) A project being analyzed by PERT has 38 activities, 16 of which are on the critical path. If the estimated time along the critical path is 90 days with a project variance of 25, what is the probability that the project will be completed in 88 days or less? A) 0.0228 B) 0.3446 C) 0.6554 D) 0.9772 E) 18 19) A PERT project has 45 activities, 19 of which are on the critical path. The estimated time for the critical path is 120 days. The sum of all activity variances is 64, while the sum of variances along the critical path is 36. What is the probability that the project can be completed between days 108 and 120? A) -2.00 B) 0.0227 C) 0.1058 D) 0.4773 E) 0.9773 20) A contractor’s project being analyzed by PERT has an estimated time for the critical path of 120 days. The sum of all activity variances is 81; the sum of variances along the critical path is 64. What is the probability that the project will take 130 or more days to complete? A) 0.1057 B) 0.1335 C) 0.8512 D) 0.8943 E) 1.29 21) Analysis of a PERT problem shows the estimated time for the critical path to be 108 days with a variance of 64. There is a .90 probability that the project will be completed before approximately day: A) 98. B) 108. C) 109. D) 115. E) 118. 22) A project whose critical path has an estimated time of 120 days with a variance of 100 has a 20% chance that the project will be completed before which day (rounded to nearest day)? A) 98 B) 112 C) 120 D) 124 E) 220 23) A project whose critical path has an estimated time of 820 days with a variance of 225 has a 20% chance that the project will be completed before which day (rounded to nearest day)? A) 631 B) 689 C) 807 D) 833 E) 1009 24) Contract requirements state that a project must be completed within 180 working days, or it will incur penalties for late completion. Analysis of the activity network reveals an estimated project time of 145 working days with a project variance of 400. What is the probability that the project will be completed before the late-payment deadline? A) 0.0401 B) 0.4599 C) 0.8056 D) 0.9599 E) near 1.0000, or almost certain 25) The ________ distribution is appropriate for calculating expected activity times and activity variances in PERT networks.