At May 1, 2017. Windsor, Inc had beginning inventory consisting of 260 units with a unit cost of \$6.0. During May, the company purchased inventory as follows: .520 units at $6.0 - 770 units at $7.0 The company sold 1290 units during the month for $10.0 per unit. Heineken uses the average cost method. The average cost per unit for May is $6.50 $6. $6.60 $7