[The following information applies to the questions displayed below.] Data for Hermann Corporation are shown below: Per Unit Percent of Sales Selling price $ 55 100% Variable expenses 33 60 Contribution margin $ 22 40% Fixed expenses are $71,000 per month and the company is selling 4,100 units per month.

Required: 1-a. How much will net operating income increase (decrease) per month if the monthly advertising budget increases by $9,500, the monthly sales volume increases by 100 units, and the total monthly sales increase by $5,500?

1-b. Should the advertising budget be increased?