Please help. I cant figure out why some of my answers are wrong

Problem 1601-4A Name Natalie Villgeas Section: Score 80% Key Code: Key code here] Instructions Answers are entered in the cells with gray backgrounds. Cells with non-gray backgrounds are protected and cannot be edited. An asterisk will appear to the right of an incorrect entry Prius Volt Company Company Materials inventory, December 1 280,280 177,000 Materials inventory, December 31 (a) 240,680 180,000 Materials purchased 712,800 342,000 Cost of direct materials used in production 752,400 (a) 339,000 Direct labor 1,058,400 (b) 516,000 Factory overhead 327,600 180,000 1,035,000 Total manufacturing costs incurred during December (b) 2,138,400 Total manufacturing costs 2,678,400 1,477,500 540,000 Work in process inventory, December 1 442,500 Work in process inventory, December 31 453,600 (c) 453,000 1,024,500 Cost of goods manufactured (c) 2,224,800 204,000 Finished goods inventory, December 1 475,200 496,800 Finished goods inventory, December 31 (d) 177,500 Sales 4,140,000 1,675,500 (d) 2,203,200 Cost of goods sold 1,051,500 Gross profit (e) 1,936,800 (e) 624,000 Operating expenses 540,000 240,000 384,000 Net income 1,396,800 VOLT COMPANY Statement of Cost of Goods Manufactured For the Month Ended December 31, 2016