What is the arithmethic mean miles per gallon?

Answer 1

Suppose you fill up your car with 10 gallons of gas and you get x miles on a trip. May be you were the only occupant. Then let's say you fill up the car with 10 gallons of gas and it gives you y miles and let's say y is less than x because you have six adults in the car and luggage in the truck and on the top of the car. Next you fill the car with 10 gallons of gas and it gives you z miles and z is less than x and also y because now you have six adults in the car, luggage in the trunk and roof of the car and you are pulling a U-Haul unit. Thus you are running the car over different conditions. Now the arithmetic mean of the miles per gallon the car gives you over these three trips would be (x + y + z)/30 which is also known as the average miles per gallon for the three trips.