23.2 Exploratory Analysis
To start, the best strategy consists in taking a look at the data and a good way to do this is through: Graph > Matrix Plot: Simple
In the previous plot, observe that there is only one car with five cylinders. Use the option Brush (see Chapter 4) to identify that this point belongs to a Volvo 850 GLT.
Also, it seems that the relationship between power and maximum speed is not linear but quadratic. We will try to confirm this impression by analyzing the corresponding residuals.