(a1) Calculate the weighted-average cost. (Round answer to 3 decimal places, e.g. 5.125.) Weighted-average cost per unit Calculate ending inventory, cost of goods sold, gross profit under each of the following methods. (1) LIFO. (2) FIFO. (3) Average-cost. (Round per unit cost to 3 decimal places, e.g. 15.647 and final answers to 0 decimal places, e.g. 5,125.)