Per Unit Percent of Sales: Selling price $ 80 100% Variable expenses 44 Contribution margin $ 36 55 45% Fixed expenses are $76,000 per month and the company is selling 2,500 units per month. Required: 1-a. How much will net operating income increase (decrease) per month if the monthly advertising budget increases by $8. and monthly sales increase by $14,400? 1-b. Should the advertising budget be increased? Complete this question by entering your answers in the tabs below.. $ Req 1A Req 18 How much will net operating income increase (decrease) per month if the monthly advertising budget increases by $8,100 and monthly sales increase by $14,400? (Round any unit calculations up to the nearest whole unit.) Net operating income by