Data for Hermann Corporation are shown below:

	Per Unit				Percent of Sales
Selling price	$	70				100	%
Variable expenses		49				70
Contribution margin	$	21				30	%

Fixed expenses are $74,000 per month and the company is selling 4,400 units per month.

Required:

1-a. How much will net operating income increase (decrease) per month if the monthly advertising budget increases by $9,800, the monthly sales volume increases by 100 units, and the total monthly sales increase by $7,000?

1-b. Should the advertising budget be increased?