... tried, including varying the threshold and performing regression analysis on various covariates (including the size of the spill in barrels, the x coordinate of plot (c)), but none succeeded in explaining ... threshold 5. The main point here is that,although there are reasons for treating the largest two observations as outliers, theyare not in fact very far from the straight line — in other words, the data ... data point as an outlier. In Figure1.10(b), the same points are plotted (including the final data point), but for the purposeof estimating the parameters, the final observation was omitted. In this...