could someone explain this plz

Question 15 (1 point) Shane has not kept accurate accounting records during the financial year. He had opening inventory of $6,700 and purchased goods costing $84,000 during the year. At the year end, he had $5,400 left in inventory. The gross profit margin ratio during the year is 20%. What is the dollar amount of Shanes gross profit for the year? For your answer, make sure to put the number without dollar signs ($), commas (,), periods (.), and decimal points. Again, please state the number only without dollar signs, commas, periods, and decimal points for your answer. For example, if the answer happens to be 12345, then you must simply put 12345