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A research project is scheduled for implementation based on the network shown. The estimated activity times and number of truck required for the research project is as indicated in Table 1. Activity Immediate Predecessors Activity Activity Expected Variance Time (t.) Activity Standard Deviation No. of Truck Required Estimate Activity Times (months) a m b 6 7 8 3 3 3 4 6 8 2 2 8 2 3 4 1 1.5 5 1.5 3 4.5 1 2 3 (A) (B) B D E F G H (a) (b) A B D, F B E,G (D (E (F (a) (6) c) (d) e) (f) (g) ACT A=4 ACT B=3 ACT C=4 ACT D = 2 ACT E = 1 ACT F = 2 ACT G = 3 ACT H = 1 (h) Table 1 Calculate the z-value, z and probability, p that the project can be completed 2 months ahead of the expected duration Te O Z-1.04 O p = 0.1492 O p = 0.0183 O Z = -1.66 OP = 0.0009 OZ -3.13 OZ-2.09 O p = 0.9817