Flounder Distribution markets CDs of numerous performing artists. At the beginning of March, Flounder had in beginning inventory 2,800 CDs with a unit cost of $6. During March, Flounder made the following purchases of CDs. March 5 March 13 3,500 @ $7 4,900 @ March 21 6,200 $9 $8 March 26 3,600 $10 During March 15,000 units were sold. Flounder uses a periodic inventory system.