Russell has started a lawn-mowing business, but it isnt going very well. His fixed costs are a truck, trailer and some equipment that has been rented for four more months at a cost of $1500. If he continues operating over these four months, the cost of labor (both his own and his employees) will be $4,000. Russell is worried about whether to keep the business going. If he expects to earn $6,000 in total revenue over the next four months, should he keep operating? Explain. What if he expects to earn $7,000 over the next four months? Explain. What if he expects to earn $8,000 over the next four months?