Data concerning Wislocki Corporation's single product appear below: Selling price Variable expenses Contribution margin Per Unit $160 40 $ 120 Percent of Sales 100% 25% 75% Fixed expenses are $1,036,000 per month. The company is currently selling 9,500 units per month. Required: The marketing manager would like to introduce sales commissions as an incentive for the sales staff. The marketing manager has proposed a commission of $10 per unit. In exchange, the sales staff would accept an overall decrease in their salaries of $110,000 per month. The marketing manager predicts that introducing this sales incentive would increase monthly sales by 520 units. What should be the overall effect on the company's monthly net-operating income of this change? Change in net operating income