Grant Company McClellan Company Materials inventory December 1 89 800 121 230 Materials inventory December 31 a 136 990 Materials purchased 228 090 272 770 Cost of direct materials used in production 240 660 a Direct labor 338 550 b Factory overhead 105 070 135 780 Total manufacturing costs incurred during December b 784 360 Total manufacturing costs 856 690 1 076 520 Work in process inventory December 1 172 420 292 160 Work in process inventory