Current Attempt in Progress Z Your answer is incorrect. Sandhill Marine Products began the year with 10 units of marine floats at a cost of $15.80 each. During the year, it made the following purchases: May 5, 30 units at $23.20; July 16, 15 units at $28.60; and December 7,20 units at $35.00. Assuming there are 25 units on hand at the end of the period, determine the cost of goods sold under (a) FIFO, (b) LIFO, and (c) average-cost. Sandhill uses the periodic approach