What is the cost of goods manufactured assuming the following data? Materials inventory, January 1 - $33,660; materials purchases - $148,800; direct labor - $120,000; work in process inventory, January 1 - $336,000; selling expense - $28,800; materials inventory, December 31 - $48,000; manufacturing overhead - $360,000; work in process inventory, December 31 - $288,000; transportation-in - $600.

what is the math behind this?