Before looking at the scatter plot again in Figure 3, we ask the reader to imagine
what line is best suggested by the data. There may be a difference of opinion here.
Some may wish to take all points into account, while others may argue that the four
points in the upper right lie outside of the pattern and therefore should be discounted.
The plot does indeed seem to suggest that most of the points (31 of them) show a rather
tight and clear pattern. Statisticians call this the “smooth”, whereas the ones that don’t
fit the general pattern are called the “rough” or “outliers”. Figure 3 shows the data
points again, together with the line that is predicted from our model, y = 0.144x.