Required information (The following information applies to the questions displayed below.] Here are some monthly data for a corporation. Selling price Variable expenses Contribution margin Per Unit $ 90 63 Percent of Sales 100% 70 30% $ 27 Fixed expenses are $78,000 per month and the company is selling 3,500 units per month. Required: 1-a. How much will net operating income increase (decrease) per month if the monthly advertising budget increases by $8,300 and monthly sales increase by $16,500? 1-b. Should the advertising budget be increased