I was out sick and missed this portion of my class. Can anyone please answer the following but provide a breakdown so I can do the others?

Data for Herron Corporation are shown below:

	Per Unit			Percent of Sales
Selling price	$	60		100%
Variable expenses		39		65%
Contribution margin	$	21		35%

Fixed expenses are $72,000 per month and the company is selling 4,200 units per month.

a.The marketing manager believes that an $9,600 increase in the monthly advertising budget would increase monthly sales by $23,000. Calculate the increase or decrease in net operating income.

b.

Refer to the original data. Management is considering using higher-quality components that would increase the variable cost by $4 per unit. The marketing manager believes that the higher-quality product would increase sales by 25% per month. Calculate the change in total contribution margin.