Pemberton products uses a periodic inventory system. The company records show the purchases of PH6; one of its items during the current month to be as follows: May 1 30 units @ $9 $ 270 May 16 20 units @ $ 12 $ 240 May 28 40 units @ $ 15 $600 90 units $1110 A physical count indicates 20 units in inventory at end of month. Determine the cost of the ending inventory and the cost of goods sold based on each