6. If the selling price increases by $1.50 per unit and the sales volume decreases by 100 units, what would be the net operating income(Do not round intermediate calculations.)

7. If the variable cost per unit increases by $.50, spending on advertising increases by $1,000, and unit sales increase by 250 units, what would be the net operating income? (Do not round intermediate calculations.)

8.What is the break-even point in unit sales? (Do not round intermediate calculations.)

9. What is the break-even point in dollar sales? (Round intermediate calculations to 4 decimal places. Round your answer to the nearest dollar amount.)