Consider the following work breakdown structure:

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

What is the estimated expected $($mean$)$ time for activity D$?$