Periodic inventory by three methods The units of an item avalable for sale during the year were as follows: Jan. 1 Inventory 2,500 units at $5 Feb, 17 Purchase 3,400 units at $7 Jul. 21 Purchase 2,700 units at $9 Nov. 23 Purchase 1,400 units at $11 There are 1,700 units of the item in the physical inventory at December 31. The periodic inventory system is used. This information has been collecte in the Microsoft Excel Online file, Open the spreadsheet, perform the required analysis, and input your answers in the questions below. Open spreadsheet a. Determine the inventory cost by the first-in, first-out mathod. b. Determine the inventory cost by the last-in, first-out method