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4. A project consists of 14 activities. The activity completion durations and the precedence relationships are as follows: [Sebuah projek terdiri daripada 14 aktiviti. Tempoh penyiapan setiap aktiviti dan hubungan keutamaan adalah seperti berikut: Activity Immediate Predecessor Duration (Days) Most Likely 3 Optimistic 2 Pessimistic A 4 B A 4 6 8 C A 3 3 3 D A 5 7 9 E B, C 2 4 6 F CD 6 7 8 G D 3 4 8 H D 2 3 4 I E, F, G 1 3 5 J F 3 5 7 K F G 4 6 8 L H 6 8 13 M I, J 2 5 8 N K, L, M 4 6 8 (a) Calculate the mean and variance of the duration of each activity assuming 99% estimation: [Kirakan purata dan varians untuk tempoh bagi setiap aktiviti dengan andaian 99% anggaran: (7 Marks/ Markah) 3 SULIT (NMJ31603) (b) Sketch the complete Activity On Node (AON) network diagram of the project. (Lakarkan gambarajah rangkaian Aktiviti Pada Nod (AON) yang lengkap untuk projek tersebut.] (14 Marks/ Markah) (c) Determine the critical path of the project and the project completion time. [Tentukan laluan kritikal projek dan masa penyiapan projek.)