Coronado Industries began the year with 12 units of marine floats at a cost of $11 each. During the year, it made the following purchases: May 5, 27 unit at $15; July 16, 20 units at $20; and December 7, 25 units at $23. Assume there are 30 units on hand at the end of the period. Coronado uses the periodic approach. Calculate average unit cost. (Round answer to 2 decimal places, e.g. 5.12.) Average unit cost $