Ieighted Average Cost Flow Method Under Perpetual Inventory System he following units of a particular item were available for sale during the calendar year: The firm uses the weighted average cost method with a perpetual inventory system. Determine the cost of merchandise sold for each sale and the inventory balance after each sale. Present the data in the form illustrated in Exhibit 5. Round unit cost to two decimal places, if necessary. nventory System or sale during the caiendar year: perpetual inventory system. Determine the cost of merchandise sold for each sole and the inventory balance after hibit 5. Round unit cost to two decimal places, if necessary