Data for hermann corporation are shown below:

Data for Hermann Corporation are shown below:

Per Unit Percent of Sales
Selling price $90 100%
Variable expenses $63 70%
Contribution margin $27 30%

Fixed expenses are $30,000 per month and the company is selling 2,000 units per month.

1-a. The marketing manager argues that a $5,000 increase in the monthly advertising budget would increase monthly sales by $9,000. Calculate the increase or decrease in net operating income.
Net operating income by

1-b. Should the advertising budget be increased?
Yes or No.