One task awaiting the researcher is to explore the association between mpg and potential predictors via plots. For example, here is the plot of mpg versus disp:
The plot reveals what we would expect: automobiles with larger displacement get lower mileage. The superimposed line is a loess fit line, which fits points locally. Recall that you can add the loess fit line via the chart editor. The pattern of points along with the loess fit line suggests nonlinearity in the association between mpg and disp. It would seem that linear regression is not suited to this data.
However, in similar ...
