A company sold a total of 1,000 units for total sales revenue of $70,000. The company incurred total variable expenses of $38,500 and total fixed expenses of $ 23,310. Based on this, the company reported a total contribution margin of $31,500 and net operating income of $ 8,190. Use this information to answer the following questions. Assume that all units are within the relevant range.

1.Calculate the per-unit contribution margin

2.Calculate the contribution margin ratio.

3. Calculate the increase in net operating income if sales increase to 1,001 units

4.Calculate the net operating income if the selling price increases by $2 per unit and the sales volume decreases by 100 units.