Helia Co is a company engaged in retail. The company uses Perpetual recording method with moving average inventory. If there is a return sale, the goods will be returned to the warehouse and no damaged inventory. Assumption there are no transactions on credit and all sales are cash. This is information supplies for Helia Co. Date Description Quantity Unit Cost or Selling Price December 31 Beginning Inventory 100 $ 18.5 January 3 Purchase 150 20 January 6 Sales 150 41 January 7 Sales Return 10 41 January 9 Purchase 75 22 January 10 Purchase Return 15 22 January 12 Sales 50 44 January 23 Purchase 100 25 January 25 Sales 160 48 January 27 Purchase 100 26 January 30 Sales 80 50 Requested: Calculate (i) cost of goods sold, (ii) ending inventory, and (iii) gross profit rate