Look again at the correlation table for cars in the previous exercise.

a) Which two variables in the table exhibit the strongest association?

b) Is that strong association necessarily cause-and-effect? Offer at least two explanations why that association might be so strong.

c) Engine displacements for U.S.-made cars are often measured in cubic inches. For many foreign cars, the units are either cubic centimeters or liters. How would changing from cubic inches to liters affect the calculated correlations involving Displacement?

d) What would you predict about the Fuel Efficiency of a car whose engine Displacement is one standard deviation above the mean?