Pina Colada Corp. uses a periodic inventory system. Its records show the following for the month of May, in which 79 units were sold. Date May 1 15 24 Explanation Inventory Purchase Purchase Total Units 30 25 45 100 Unit Cost $9 10 11 Total Cost $270 250 495 $1,015 (a) Calculate the weighted average unit cost. (Round answer to 3 decimal places, e.g. 5.125.) Weighted average unit cost $