Question: Stan Moneymaker needs 15 gallons of gasoline to top off his automobile's gas tank. If he drives an extra eight miles (round trip) to a gas station on the outskirts of town, Stan can save $0.10 per gallon on the price of gasoline. Suppose gasoline costs $3.90 per gallon and Stan's car gets 25 mpg for in-town driving. Should Stan make the trip to get less expensive gasoline? Each mile that Stan drives creates one pound of carbon dioxide. Each pound of CO2 has a cost impact of $0.02 on the environment. What other factors (cost and otherwise) should Stan consider in his decision making?