Zoe Mahaffey
Per.4
Weight of a Car vs. Combined Gas Mileage
With the increase of gas prices these days, wouldn’t you want to know an easy way to
spend less? I chose the weight of a car vs. its combined gas mileage (the average of highway
and city quotes) as my linear regression project because I haven’t ever heard of any one
comparing these two things before. I wanted to have an original project idea that no one else
would have. Right now gas prices are sky high and if you are going to buy a new car you
probably want to buy one that gets good gas mileage so try and buy a lighter car. It’s bound to
get better gas mileage than cars of similar size.
Combined Miles Per Gallon
Weight vs. Gas Mileage
50
y = -.013x + 62.023
r = .872
40
30
20
10
0
0
1000
2000
Weight in Pounds
3000
4000
The r value of my data is about .872. This means that the comparison of the weight of a
car and its combined gas mileage pretty much fits together in a linear fashion. The linear
regression equation of this data set is y = -.013x + 62.023. The slope is -.013. This means that
for every pound of weight in a car; there is a decrease of .013 miles per gallon in combined gas
mileage. The y intercept is 62.023; this means that when the weight is zero pounds then the
combined miles per gallon of gas mileage is 62.023. Note: this can’t actually happen because
cars never weigh zero pounds.
I predict that if the weight of a car is 4000 pounds then its combined gas mileage would
be 10.023 miles per gallon. Similarly, if the weight of a car is 1000 pounds then its gas mileage
would be 49.023 miles per gallon, and for 2500 pounds it would be 29.532 miles per gallon. I
got these numbers by substituting the weight for x and then solving for y to get the predicted
miles per gallon.
Some of the careers that could use my analysis are, car building companies that are
trying to market to people who want to spend less on gas. With gas prices right now most
people are trying to useless so they can save money. Also, environmentalists who are trying to
convince people to burn less fossil fuels in their cars could use the data. Scientists who design
materials that are strong and light weight can market their materials to car manufactures. All of
these careers are affected by the data that I have collected.
The weight of a car and its combined gas mileage is globally relevant because cars are
manufactured and shipped around the world. It costs a lot more to ship a heavy car than a light
car. Right now because of global issues, such as those going on in the Middle East; oil and gas
prices have sky rocked to almost four dollars a gallon in the US, and the equivalent of almost
nine dollars per gallon in the UK. People all over the world are trying to find a way to spend less
on gas.
This data is valid, and almost linear. It could be used in a number of global ways to help
people when buying, marketing, or producing cars. Because it is almost linear it makes it easy to
predict more points that are not in the data set accurately. When people are buying a car or
when companies are manufacturing cars they should take the weight into account because it
makes a huge difference in the gas mileage that the car gets. The lighter the car the less gas it
uses and the more people save; therefore, the more people want to invest in that car and the
less it contributes to global warming and harming the earth.
Works Cited:
This is where I found the weights of cars: http://www.hondacivicforum.com/forum/generalcivic-talk-16/honda-weight-list-8863/?ref=esp-link
This is where I found the combined miles per gallon: http://www.fueleconomy.gov/ (I searched
for each type of car and recorded the data)