what is the answer?

Data for Hermann Corporation are shown below: Fixed expenses are $30.000 per month and the company is selling 2,000 units per month. Exercise 5.7 (Static) Part 1 Required: 1-a. How much will net operating income increase (decrease) per month if the monthly advertising budget increases by $5,000, the monthly sales volume increases by 100 units, and the total monthly sales increase by $9,000? 1-b. Should the advertising budget be increased