Three identical units of merchandise were purchased during July, as follows: Date uly 3 10 24 Product I Purchase Purchase Purchase Total Units Cost $25.00 28.00 31.00 $84.00 Average cost per unit $28.00 Assume one unit sells on July 28 for $40.00 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 Gross Profit Cost of Goods Sold Ending Inventory a) First-in, first-out b) Last-in, first-out c) Average