Riverbed Corp uses a periodic inventory system. Its records show the following for the month of May, in which 75 units were sold. Date Explanation Units Unit Cost Total Cost May 1 Inventory 34 $8 $272 15 Purchase 26 9 234 24 Purchase 40 10 400 Total 100 $906 (a) Calculate the weighted-average unit cost. (Round answer to 3 decimal places, e.g. 5.125.) Weighted-average unit cost $Enter the Weighted-average unit cost in dollars______