Problem 6-9A Wittmann Co. began operations on July 1. It uses a perpetual inventory system. During July, the company had the following purchases and sales. Purchases Date Units Unit Cost Sales Units July 25 $122 July 6 15 July 11 35 $136 July 14 25 July 21 40 $147 July 27 25 Don't show me this message again for the assignment