Calculating and Using a Single Charging Rate

The expected costs for the Maintenance Department of Stazler, Inc., for the coming year include:

Fixed costs $($salaries$,$ tools$)$: $$74,750$ per year

Variable costs $($supplies$)$: $$1\mathrm{.}45$ per maintenance hour

Estimated usage by:

$\backslash$table$[[$Assembly Department,$4,900],[$Fabricating Department,$6,900],[$Packaging Department,$11,200],[$Total maintenance bours,$23,{000}_{?}$