Production: Beginning inventory 1,600 units that are 100% complete as to materials and 30% complete as to conversion costs; units started during the period are 18,400; ending inventory of 5,000 units 10% complete as to conversion costs. Manufacturing costs: Beginning inventory costs, comprised of $20,000 of materials and $43,180 of conversion costs; materials costs added in Polishing during the month, $177,200; labor and overhead applied in Polishing during the month, $102,680 and $257,140, respectively