Oslo Company prepared the following contribution format income statement based on a sales volume of $1,000$ units $($the relevant range of production is $500$ units to $1,500$ units$)$:

Sales $ $10,000$

Variable expenses $5,500$

Contribution margin $4,500$

Fixed expenses $2,250$

Net operating income $ $2,250$

$7.$ If the variable cost per unit increases by $$1,$ spending on advertising increases by $$1,000,$ and unit sales increase by $100$ units, what would be the net operating income?