Q$7.$ Fancy Doors, Inc., produces two types of doors, interior and exterior. The company's simple costing system has two direct cost categories $($materials and labor$)$ and one indirect cost pool. The simple costing system allocates indirect costs based on machine$-$hours. Recently, the owners of Fancy Doors have been concerned about a decline in the market share for one of their products, usually their bigger seller. Information related to Fancy Doors production for the most recent year follows:

$\backslash$table$[[,$Interior,Exterior$],[$Units sold,$3,200,1,800],[$Selling price,$$250,$$$400$