The $423 in part 1 is wrong but the "operating income" is correct according to the homework system

Required information (The following information applies to the questions displayed below.) Monterey Co. makes and sells a single product. The current selling price is $13 per unit. Variable expenses are $7.8 per unit, and fixed expenses total $27,340 per month. (Unless otherwise stated, consider each requirement separately.) Management is considering a change in the sales force compensation plan. Currently each of the firm's two salespeople is paid a salary of $2,500 per month. 9-1. Calculate the monthly operating income (or loss) that would result from changing the compensation plan to a salary of $400 per month, plus a commission of $0.95 per unit, assuming a sales volume of 5,450 units per month. (Do not round intermediate calculations.) Operating income $ 423 g-2. Calculate the monthly operating income (or loss) that would result from changing the compensation plan to a salary of $400 per month, plus a commission of $0.95 per unit, assuming a sales volume of 6,100 units per month. (Do not round intermediate calculations. Losses should be indicated by a minus sign.) h-1. Assuming that the sales volume of 6,100 units per month achieved in part g could also be achieved by increasing advertising by $1,000 per month instead of changing the sales force compensation plan. What would be the operating income or loss? (Do not round intermediate calculations. Losses should be indicated by a minus sign.) Operating income