Inventory Costing Methods-Perpetual Method The Lippert Company uses the perpetual inventory system. The following July data are for an item in Lippert's inventory: Caiculate the cost of goods sold for the July 15 sale using (a) first-in, first-out, (b) last-in, first-out, and (c) the weighted-average cost methods. Round your final answers to the nearest dollar. For weighted-average cost, do not round the weighted-average unit cost