Data concerning Wislocki Corporation's single product appear below: Selling price Variable expenses Contribution margin Per Unit $ 170 51 Percent of Sales 100% 30% $ 119 70% Fixed expenses are $1,052,000 per month. The company is currently selling 9,800 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 $102,000 per month. The marketing manager predicts that introducing this sales incentive would increase monthly sales by 480 units. What should be the overall effect on the company's monthly net operating income of this change? Change in net operating income