What is the estimated expected $($mean$)$ time for project completion?

$\backslash$table$[[$Activity$,\backslash$table$[[$Start$],[$Node$]],\backslash$table$[[$Finish$],[$Node$]],\backslash$table$[[$Optimistic Time$],[$Estimates $($days$)]],\backslash$table$[[$Most Likely Time$],[$Estimates $($days$)]],\backslash$table$[[$Pessimistic Time$],[$Estimates $($days$)]]],[$A$,1,2,41,50,59],[$B$,1,3,54,60,66],[$C$,2,4,58,70,82],[$D$,3,,32,41,44]]$

$221$ days

$41$ days

$100$ days

$120$ days

$70$ days