1. Miles Per
Gallon
By: Jessica Freeman
Class: F

2. Data
Year MPG
1950 14.8
1960 13.9
1970 13.4
1980 13.5
1990 15.5
1995 18.3

3. Graph

4. Work
Prediction
14.8=a(1950-1970)^2+13.4 The Data that I received from the graph was
14.8=a(20)^2+13.4 inaccurate, since it gave me an incorrect
14.8=400a+13.4 equation. When I tried to use the equation excel
-13.4 -13.4 gave me, I received the answer of -17 for my
1.4=400a MPG for a 2011. Which is obviously incorrect, so I
0.0035=a had to create my own equation. This is because
y= 0.0035(x-1970)^2+13.4 excel is program created by humans and people
y= 0.035(2011-1970)^2 make mistakes. So to predict how much a 2011
y= 0.0035(41)^2+13.4 car would get for gas mileage according to the
y= 0.0035(41)^2+13.4 data, I had to create my own equation. I did this
y= 0.0035(1681)+13.4 by using the standard quadratic equation of y=a(x-
y= 19.2835 – round to 19.3 h)^2. I then used the vertex (1970, 13.4) as my h
19.3 mpg predicted for a and k, and the point (1950, 14.8) as my x and y.
2011 car After plugging this into the equation of y=a(x-
h)^2, I received 0.0035 as my a. I then used my a
to come up with the correct equation of, y=
0.0035(x-1971)^2+13.4.
I then in plugged 2011 as my x and I got 19.3 as
my predicted MPG for a 2011 car.

5. Actual MPG for 2011 Car
A 2011 Honda
CR-Z actually
gets 34 MPG.
This because
the car is
actually a
hybrid and is
made to be
more fuel
efficient.

6. Gas Mileage Graph

7. How Speed affects Gas Mileage
Using the graph for how speed affects gas mileage, I was able to figure
out that at 35 MPH the car would get 29 MPG. I figured this out by
using the graph's equation of y= -0.0108x^2+0.9811x+8.0481. I then
plugged in the 35 MPH for x and I came up with 29 for my MPG. So this
shows that when you drive at 35 MPH, you get a gas mileage of 29
MPH. Also the speed for which the car’s gas mileage is the maximum
is 45 MPH. I figured this out by using the equation of –b/2a. I plugged
in the -b, -0.9811 from the data’s equation into maximum equation
and divided it by the a, -0.0108 multiplied by 2. This then gave me the
speed of 45 MPH. I also could have figured this out though, by looking
at my data and seeing that after 45 MPH, at 65 MPH the MPG
decreased for the first time in my data. Showing that the faster you
drive the worst gas mileage you get.

8. Speech
Overall, from the data I gathered and graphs I created, I saw that as we have
come more into the future, the gas mileage for car has improved. These days
in 2011, there are even hybrid, fuel efficient cars that are designed specifically
to get better gas mileage. In the case of the car, I chose to compare to my
predicted MPG for a 2011 car to, the Honda CR-Z is actually a fuel efficient
hybrid that gets really good gas mileage. This car gets 34 MPG, and my
prediction was only 19.3 MPG, an almost 15 miles difference. If I had chosen a
non hybrid car like a 2011 Toyota Camry for example, it would have gotten 26
MPG. Which is still, almost 7 miles more, which is a significant increase
considering that according to my data, over 10 years the gas mileage only went
up about 1 or 2 miles per gallon. Also from my data, I was able to prove that the
faster you drive the worse gas mileage you get. Also overall, while finding my
data for the gas mileage per year, I encountered problems with the excel
program it’s self, and I was able to learn the importance of checking for human
error, even while working on the computer.