The Accounts for a Manufacturing Company for an Accounting Period

The accounts for a manufacturing company for an accounting period are listed below.Find the unknown amounts indicated by question marks.
$\begin{array}{|l|r|}\hline \text { Sales } & \$ 39,000 \\\hline \text { Cost of goods sold } & ? \\\hline \text { Purchases of direct materials } & \$ 11,000 \\\hline \text { Direct labour } & \$ 5,000 \\\hline \text { Finished goods inventory, beginning } & \$ 5,000 \\\hline \text { Work in process, beginning } & \$ 800 \\\hline \text { Work in process, ending } & \$ 3,000 \\\hline \text { Gross margin } & \$ 11,700 \\\hline \text { Finished goods inventory, ending } & ? \\\hline \text { Accounts payable, beginning } & \$ 4,000 \\\hline \text { Accounts payable, ending } & \$ 2,800 \\\hline \text { Direct materials inventory, beginning } & \$ 1,000 \\\hline \text { Direct materials inventory, ending } & \$ 3,000\\\hline \text { Indirect labour } & \$ 2,000 \\\hline \text { Indirect materials used } & \$ 4,000 \\\hline \text { Utilities expense, factory } & \$ 3,000 \\\hline \text { Depreciation on factory equipment } & \$ 7,000\\\hline\end{array}$