Access the data about the gas mileages of all 2014 cars, which are available at MyMathLab and at the Pearson Downloadable Student Resources for Math & Stats website. When constructing relative frequency histograms for parts (a) and (b), begin with lower class limit 5 miles per gallon and class width 5 miles per gallon.
a. Describe the highway gas mileages (in miles per gallon) by using a dotplot, a stemplot, and a relative frequency histogram. Compare how helpful the diagrams are in analyzing the data.
b. Construct a relative frequency histogram that describes the city gas mileages (in miles per gallon) of the cars. Compare the spreads of the city-gas-mileage distribution and the highway-gas-mileage distribution.
c. Find the class that contains the 50th percentile of the city gas mileages. Find the class that contains the 50th percentile of the highway city gas mileages. Compare your two results. What does this mean in this situation?
d. Construct a dotplot of the highway gas mileages where the mileages are grouped by the number of cylinders. As the number of cylinders increases, what tends to happen to the highway gas mileage? Can you assume there is causality? Explain.
e. A student says front-wheel drive is more fuel efficient than rear-wheel drive, which is more fuel efficient than four-wheel drive. To investigate, construct a dotplot of the high- way gas mileages where the mileages are grouped by the drive description. Is the student correct? Explain.