Periodic Inventory by Three Methods The units of an item avallable fot sale during the yeaf were as follows: There ace 8 units of the item in the physical inventory at December 31. The periodic imventory system is used; Round average unit cost to the nearest cent and final answers to the nearest whole dollar, if required. a. Determine the inventory cosk by the firstiti, first-out method. b. Determine the inventory cost by the lastein, first-out methodi c. Determine the inventory cost by the wighted averege cast method, Round average unit cost to the two decimal places, and round your final answer to the nearest doliar