Wrobbel Corporation produces and sells a single product. Data concerning that product appear below: Per Unit Percent of Sales 100% 20% Selling price Variable expenses $200 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, markeung 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