A consumer magazine collected the following data for the fuel efficiency of cars (miles per gallon) compared to weight (thousands of pounds).

$e=49−8.4w$
$w$ is the weight ($1000\text{s}$ of pounds)
and $e$ is the fuel efficiency (mpg).

1. What does the $−8.4$ in the equation represent? What are the units on this number?

   Hint (a):

   This is a linear equation.

   Answer (a):

   $−8.4$ is the slope of the line of best fit.
   Its units are mpg/$1000$ pounds.

2. What does the 49 in the equation represent? What are its units?

   Hint (b):

   Consider Hint (a).

3. Describe the association between fuel efficiency and weight.

   Answer (c):

   Moderately strong negative linear association with no apparent outliers.

4. Cheetah Motors has come out with a super lightweight sports utility vehicle (SUV) that weighs only $2800$pounds. What does the model predict the fuel efficiency will be?

   Hint (d):

   Use the graph to come up with a prediction of the fuel efficiency of the new SUV.