By using activity compression at the lowest cost, make the best combination to shorten the project duration by $4$ days.

$\backslash$table$[[$ACTIVITY$,\backslash$table$[[$ESTIMATED$],[$DURATION$]],\backslash$table$[[\backslash$table$[[$DURATION$],[$WITH$],[$COMPRESSION$]]]],\backslash$table$[[$REDUCTION$],[$OF DAYS$]],\backslash$table$[[$COST PER$],[$DAY$]],\backslash$table$[[$COST OF$],[$COMPRESSION$]]],[$K$,8,5,3,$$$,12,000,$$$,36,000],[$L$,5,4,1,$$$,5,000,$$$,5,000],[$M$,6,4,2,$$$,3,000,$$$,6,000],[$N$,4,3,1,$$$,4,000,$$$,4,000],[0,5,3,2,$$$,2,000,$$$,4,000],[$P$,9,7,2,$$$,7,000,$$$,14,000],[$Q$,3,1,2,$$$,2,000,$$$,4,000]]$

You do not need to draw up the red diagram.

Create an Excel table where you make all the possible combinations with which the $4-$day reduction is achieved at the lowest cost.