Data for Hermann Corporation are shown below:

$\backslash$table$[[,$Per Unit,$\backslash$table$[[$Percent$],[$of Sales$]]],[$Selling price,$$120,1008],[$Variable expenses,$78,65],[$Contribution margin,$$42,358]]$

Fixed expenses are $$84,000$ per month and the company is selling $2,600$ units per month.

Required:

$1-$a$.$ How much will net operating income increase $($decrease$)$ per month if the monthly advertising budget increases by $$8,900,$ the monthly sales volume increases by $100$ units, and the total monthly sales increase by $$12,000?$

$1-b.$ Should the advertising budget be increased?

Complete this question by entering your answers in the tabs below.

How much will net operating income increase $($decrease$)$ per month if the monthly advertising budget increases by $$8,900,$ the monthly sales volume increases by $100$ units, and the total monthly sales increase by $$12,000?($Do not round intermediate calculations.$)$