Consider the following costs of owning and operating a car. An $18,000 Fiat 500 Pop financed over 60 months at 4 percent interest means a monthly payment of $331.50. Insurance costs $120 a month regardless of how much you drive. The car gets 35 miles per gallon and uses regular-grade gasoline that costs $2.60 per gallon. Finally, suppose that wear and tear on the car costs about 20 cents a mile. Which costs are fixed, and which are variable? What is the marginal cost of a mile driven? In deciding whether to drive from Atlanta to Las Vegas (about 2,000 miles round-trip), which costs would you consider? Why?