Crane Company uses a perpetual inventory system and reports the following for the month of June. (a1) Calculate the weighted-average cost per unit, using a perpetual inventory system. Assume a sale of 400 units occurred on June 15 for a selling price of $9 and a sale of 50 units on June 27 for $10. (Round intermediate calculations to 0 decimal places, e.g. 152 and final answers to 3 decimal places, e.g. 5.125.)