6-18 Activity-based costing, manufacturing. Decorative Doors, Inc., produces two types of doors, interior and exterior. The company's simple costing system has two direct cost categories (mate- rials and labor) and one indirect cost pool. The simple costing system allocates indirect costs on the basis of machine-hours. Recently, the owners of Decorative Doors have been concerned about a decline in the market share for their interior doors, usually their biggest seller. Information related to Decorative Doors production for the most recent year follows. Exterior Interior 3,200 125 $ 30 S 16 Units sold Selling price Direct material cost per unit Direct manufacturing labor cost per hour Direct manufacturing labor-hours per unit Production runs Material moves Machine setups Machine-hours Number of inspections 1,800 200 s 45 S 16 1.50 2.25 40 72 45 5,500 250 85 168 155 4,500 150 The owners have heard of other companies in the industry that are now using an activity-based costing system and are curious how an ABC system would affect their product costing decisions. After analyzing the indirect