Skysong Company sells one product. Presented below is information for January for Skysong Company. Skysong uses the FIFO cost flow assumption. All purchases and sales are on account. (a) Your answer is correct. Assume Skysong uses a periodic system. Prepare all necessary journal entries, including the end-of-month closing entry to record cost of goods sold. A physical count indicates that the ending inventory for January is 105 units. (If no entry is required, select "No entry" for the account titles and enter 0 for the amounts. Credit account titles are automatically indented when amount is entered. Do not indent manually.) Compute gross profit using the periodic system. Gross profit $