Periodic and Perpetual Systems-Calculating Ending Inventory and Cost of Sales Using Average Cost (Moving Average), FIFO, and LIFO Undew Inc.'s inventory records showed the following data for an item it sells regularly. 3. LIFO (perpetual) - Note: Do not use negative signs with any of your answers. - Note: On each date, list the inventory units in chronological order based on their purchase date with beginning inventory, if any, listed first