Mo's Motors had the following purchase transactions in December: Dec. 4 Purchased $6,800 of merchandise on account from Engine Central, terms 2/15, net 30. 7 Mo returned $1,300 of merchandise because he changed his mind and wanted to order a different type of engine. 16 Mo paid the balance owing to Engine Central. Prepare the journal entries to record the purchase transactions on the books of Mo's Motors using a perpetual inventory system. (Credit account titles are automatically indented when the amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter O for the amounts.) Date Account Titles and Explanation Debit Credit Entry" for the account titles and enter O for the amounts.) Date Account Titles and Explanation Debit Credit