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Required information [The following information applies to the questions displayed below.] Trey Monson starts a merchandising business on December 1 and enters into the following three inventory purchases. Monson uses a perpetual inventory system. Also, on December 15 , Monson sells 15 units for $39 each. etermine the costs assigned to ending inventory when costs are assigned based on the weighted average method. (Round your per iit costs to 2 decimal places.)