Wrobbel Corporation produces and sells a single product. Data concerning that product appear below: Percent of Sales 100% 20% Per Unit $200 Selling price Variable expenses 40 Contribution margin $160 80% Fixed expenses are $120,000 per month. The company is currently selling 1,300 units per month. Management is considering using a new component that would increase the unit variable cost by $49 Since the new component would improve the company's product, the marketing manager predicts that monthly sales would increase by 500 units. Required: What should be the overall effect on the company's monthly net operating income of this change if fixed expenses are unaffected? (Negative amount should be indicated by a minus sign.) Change in net operating income