Skysong Company sells one product. Presented below is information for January for Skysong Company. Jan. 1 Inventory 106 units at $5 each 4 Sale 85 units at $8 each 11 Purchase 155 units at $7 each 13 Sale 128 units at $9 each 20 20 Purchase 173 units at $7 each 27 Sale 116 units at $11 each Skysong uses the FIFO cost flow assumption. All purchases and sales are on account. 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 O for the amounts. Credit account titles are automatically indented when amount is entered. Do not indent manually.) Date Account Titles and Explanation in.4 Accounts Receivable Sales Revenue Debit Credit 680 680