Required information Trey Monson starts a merchandising business on December 1 and enters into the following three inventory purchases. Also, on December 15 , Monson selis 23 units for $30 each. Required: Monson sells 23 units for $30 each on December 15. Of the units sold, 10 are from the December 7 purchase and 13 are from the December 14 purchase. Monson uses a perpetual inventory system. Determine the costs assigned to the December 31 ending inventory when costs are assigned based on specific identification