What is the unit cost used to calculate the cost of goods sold, if a company uses the Perpetual system and the average cost assumption? Total cost of goods available for sale / Total units of goods available for sale, after each purchase within the accounting period Total cost of goods available for sale / Total units of goods available for sale, for the accounting period Total purchase cost / Total units purchased, for the accounting period Total purchase cost / Total units purchased, after each purchase within the accounting period