7 The following data refer to one year for Monroe Fabricators. Fill in the blanks. Direct materials inventory, January 1 Direct materials inventory, December 31 $ 2,720 Work-in-process inventory, January 1 2,660 Work-in-process inventory, December 31 3,740 1:39:51 Finished goods inventory, January 1 1,790 Finished goods inventory, December 31 290 Purchases of direct materials 15,970 Cost of goods manufactured during the year 53,440 Total manufacturing costs Cost of goods sold Gross margin 54,940 48,410 Direct labor Direct materials used 14,440 Manufacturing overhead 13,760 Sales revenue