Campbell Corporation paid one of its sales representatives $7,000 during the month of March. The rep is paid a base salary plus $12 per unit of product sold. During March, the rep sold 160 units. Required Calculate the total monthly cost of the sales representative's salary for each of the following months. April May June July 200 110 210 120 Month Number of units sold Total variable cost Total fixed cost Total salary cost $ 0 $ 0 $ 0 $