Develop and ABC categorization. If an item value is less than $20\%$ of total value, then $C$ items, if between $20$ and $80\%,$ then B items, if more than $80\%$ of total value then A items.

$\backslash$table$[[$ITEM CODE,AVERAGE INVENTORY$($UNITS$),$VALUE $($$$/$UNIT$)],[$A$,400,3\mathrm{.}75],[$B$,300,4\mathrm{.}00],[$C$,120,2\mathrm{.}50],[$D$,75,1\mathrm{.}50],[$E$,60,1\mathrm{.}75],[$F$,30,2\mathrm{.}00],[$G$,20,1\mathrm{.}15]]$