Gomez Company has two service departments $($Personnel and Office$)$ and two operating departments $($Shoes and Clothing$).$ Following are the direct expenses and square feet occupied by the four departments, and the total sales for the two operating departments.

$\backslash$table$[[$Department$,$Direct Expenses,Square Feet,Sales$],[$Personnel$,$$$18,000,400,],[$Office$,30,000,400,],[$Shoes$,102,000,1,600,$$$150,000$