A car’s power output is primarily influenced by the size of its engine. A sample of 90 different car models of three makes from the European market is stored in the file Cars . Develop a simple regression model to predict power output (kW), based on engine size (displacement, in cubic centimeters).

a. Construct a scatter plot.
For these data, b0 = -44.878 and b1 = 0.081.

b. Interpret the meaning of the slope, b1, in this problem.

c. Predict the mean power output for cars with a displacement of 2,000 cm3.

d. What conclusion can you reach based on the results of (a)–(c)?