Regional Rent-A-Car is interested in studying how weight of a vehicle is related to the fuel
efficiency for several of its rental vehicles.
A random sample of 15 vehicles from Regional Rent-A-Car yielded the data in the table
on the left.
REGIONAL RENT-A-CAR
Fuel Efficiency (in
mpg)
32.7
22.8
18.6
26.1
18.4
26.2
33.1
Weight
(in pounds)
2000
3123
3775
2287
4000
2485
2114
2433
2525
2889
3186
3258
3622
28.3
26.2
22.5
20.9
21.3
18.1
Part A: Identify and interpret in context the
estimate of the slope for the least-squares
regression line. (5 points)
Part B: Identify and interpret in context the
correlation coefficient. (5 points)
Part C: A car weighing 2,684 pounds had an
average fuel efficiency of 24.6 miles per gallon.
What is this car's residual? (5 points)
Part D: Estimate the weight of a vehicle whose fuel
efficiency is 20.2 miles per gallon. (5 points)
Part E: Is this model the best fit for the data?
Explain your reasoning. If a transformation is
required, what is the equation for the new model?
Show your work. (5 points)
Part F: Using the transformation you gave in Part E,
what would be the new estimate for fuel efficiency
of the vehicle weighing 2,684 pounds? What effect
did this new model have on the residual, compared
to the result you found in Part C? Show all work. (5
points)