Dave's earliest start $($ES$)$ and earliest finish $($EF$)$ are:

$\backslash$table$[[$Activity$,$ES$,$EF$],[$A$,0,7],[$B$,0,6],[$C$,7,11],[$D$,7,9],[$E$,6,9],[$F$,6,12],[$G$,11,22],[$H$,12,19]]$

Dave's latest start $($LS$)$ and latest finish $($LF$)$ are:

$\backslash$table$[[$Activity$,$LS$,$LF$],[$H$,15,22],[$G$,11,22^($TT$)],[$F$,9,15^($TT$)],[$E$,8,11],[$D$,13,15],[$C$,7,11],[$B$,2,8],[$A$,0,7]]$

The slack times are:

$\begin{array}{cc}\text{A}\text{c}\text{t}\text{i}\text{v}\text{i}\text{t}\text{y}& \text{S}\text{l}\text{a}\text{c}\text{k}\\ A& 0\\ B& 2\\ C& 0\\ D& \end{array}$