December 2: The U. S. Environmental Protection Agency (EPA) began on this date in 1970. The roles of the EPA are to protect human health and to safeguard the natural environment (air, water, and land). The EPA monitors the fuel economy tests that vehicle manufacturers use to advertise the gas mileage of their vehicles. The last time you filled the gas tank on your car, the odometer read 72,369 miles. Now the odometer reads 72,831 miles and you just spent $56 to fill the tank. The price of gas is $4/gallon. What was the fuel economy of your car since your last fill-up?