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 $ $90,000$

Variable expenses $49,500$

Contribution margin $40,500$

Fixed expenses $33,210$

Net operating income $ $7,290$

$7.$ If the variable cost per unit increases by $$1,$ spending on advertising increases by $$1,800,$ and unit sales increase by $260$ units, what would be the net operating income? $($Round "Per Unit" calculations to $2$ decimal places$)$

$8.$ What is the break$-$even point in unit sales? $($Round intermediate calculations to $2$ decimal places.$)$

$13.$ Using the degree of operating leverage, what is the estimated percent increase in net operating income that would result from a $5\%$ increase in unit sales? $($Round your intermediate calculations and final answer to $2$ decimal places.$)$

$14.$ Assume that the amounts of the company$$s total variable expenses and total fixed expenses were reversed. In other words, assume that the total variable expenses are $$33,210$ and the total fixed expenses are $$49,500.$ Under this scenario and assuming that total sales

$15.$ Assume that the amounts of the company$$s total variable expenses and total fixed expenses were reversed. In other words, assume that the total variable expenses are $$33,210$ and the total fixed expenses are $$49,500.$ Using the degree of operating leverage, what is the estimated percent increase in net operating income of a $5\%$ increase in unit sales? $($Round your intermediate calculations and final answer to $2$ decimal places.$)$