Franklin Corporation paid one of its sales representatives $7,500 during the month of March. The rep is paid a base salary plus $10 per unit of product sold. During March, the rep sold 130 units. Required Calculate the total monthly cost of the sales representative's salary for each of the following months. Month Aprili May June July Number of units sold 170 80 180 90 Total variable cost Total fixed cost Total salary cost $ 0 $ 0 $ 0 $ 0