Consider the network described in the table below.

Immediate Optimistic Likely Pessimistic

$\backslash$table$[[$Activity$,\backslash$table$[[$Time$],[$Predecessor$($s$)],[($days$)]],\backslash$table$[[$Time$],[($days$)]],\backslash$table$[[$Time$],[($days$)]]],[$W$,$none,$4,6,14,,],[$H$,$none,$7,10,13,,],[$C$,$W$,3,5,7,,],[$G$,$H$,4,6,8,,],[$E$,$H$,3,3,3,,],[$F$,$C$,$E$,1,4,10,,]]$

What is the probability of completing the project in $15$ days or less?