Given the activities described by the following table:

$\backslash$table$[[$Activity$,\backslash$table$[[$Expected$],[$Time$]],\backslash$table$[[$STD of$],[$Time$],[$Estimate$]],\backslash$table$[[$Immediate$],[$Predecessor$],[($s$)]]],[$a$,7,2,-],[$b$,3,1,$a$],[$c$,9,3,$a$],[$d$,4,1,$b$,$c$],[$e$,5,1,$b$,$c$],[$f$,8,2,$e$],[$g$,8,1,$d$,$f$],[$h$,6,2,$g$]]$

a$.$ What is the project completion time?

b$.$ What is the project standard deviation?

c$.$ Find the probability that the project will take more than $49$ time periods to complete?