PRI Blue Inc. uses a perpetual inventory system. Its records show the following for the month of May. Date May May 15 May May 18 24 Explanation Units Inventory Purchase Sale Purchase Total 31 24 (43) 39 51 Unit Cost $8 9 10 Total Cost $248 216 390 $854 Calculate the cost of goods sold for May and the ending inventory at May 31 using the average cost formula. (For average, use 3 decimal places, e.g. 15.235 in your calculations and round final answers to 2 decimal places, eg 5.25.)