Quarter First Second Third Fourth Direct materials $240,000 $120,000 $ 60,000 $180,000 Direct labor 128,000 64,000 32,000 96,000 Manufacturing overhead 300,000 220,000 180,000 ? Total manufacturing costs (a) $668,000 $404,000 $272,000 $ ? Number of units to be produced (b) 80,000 40,000 20,000 60,000 Estimated unit product cost (a) = (b) $ 8.35 $ 10.10 $ 13.60 $