Please read Lecture $5$ slides $47-67.$ The problem below is similar to the example for a construction

project in slides $63-67.$

A project consists of $10$ work packages $($activities A $$ J$).$ Your instructor has developed a network

diagram and used CPM to find the critical path. The activities along the critical path are A$-$C$-$D$-$G$-$I$-$J$.$

Activity

Time Estimates $($Duration$)$

in days

Low Mode High

A $91622$

B $81420$

C $568$

D $161823$

E $223033$

F $71012$

G $212429$

H $5810$

I $121821$

J $246$

a$)$ Find the expected duration of the project, its variance and standard deviation

b$)$ What$$s the probability $($expressed in $\%)$ of completing the project in more than $13$ weeks?