56.5 Horne Inc. uses a periodic inventory system. Its records show the following for the month of May, in which 74 units were sold. Units Date May 1 30 Explanation Inventory Purchase Purchase Total Unit Cost $ 9 10 Total Cost $270 250 418 15 38 $938 Instructions Calculate the ending inventory at May 31 using the (a) FIFO, (b) LIFO, and (c) average- cost methods. (For average-cost, round the average unit cost to three decimal places.) Prove the amount allocated to cost of goods sold under each method