Three identical units of merchandise were purchased during July, as follows: Date Product T Units Cost July 3 Purchase 1 $25 10 Purchase 1 28 24 Purchase 1 31 Total 3 $84 Average cost per unit $28 Assume one unit sells on July 28 for $40. Determine the gross profit, cost of goods sold, and ending inventory on July 31 using (a) first-in, first-out, (b) last-in, first-out, and (c) average cost flow methods. Gross Profit Cost of Goods Sold Ending Inventory a. First-in, first-out $fill in the blank 1 $fill in the blank 2 $fill in the blank 3 b. Last-in, first-out $fill in the blank 4 $fill in the blank 5 $fill in the blank 6 c. Average $fill in the blank 7 $fill in the blank 8 $fill in the blank 9?