Repeat Exercise 17.9, but for a third-order model and using y = top speed (mph) as the dependent variable. During the 1960s, manufacturers of the so-called “muscle cars” were accused of deliberately understating the massive amount of horsepower these engines produced. Examining the curve for the third-order model, would it appear that these accusations might have been justified?
Repeat exercise
An early edition of Car and Driver magazine reported the engine horsepower, top speed (mph), curb weight (pounds), and 0–60 mph acceleration time (seconds) for a selection of automobiles that ranged from large American “muscle cars” to small economy imports. The data are in file XR17009. Using y = 0–60 time and x = horsepower, fit a second-order polynomial model and predict the 0–60 time for a car with 300 horsepower.