Gibson Corporation paid one of its sales representatives $9,500 during the month of March. The rep is paid a base salary plus $11 per unit of product sold. During March, the rep sold 120 units. Required Calculate the total monthly cost of the sales representative's salary for each of the following months: Month Number of units April May June July 160 70 170 80 Total variable cost Total fixed cost Total salary cost $ 0 $ 0 $ 0 $ 0