[Click on image for larger view.] Figure 2: Naive Modify Predict Function vs. Using a Quantile Loss Function The ideas are illustrated by the graph in Figure 2. The hypothetical graph shows a linear ...

Your graph would then look like this ... The best way is to use a spreadsheet and the QUARTILE function. For example, the function "=QUARTILE(A1:A53,1)" returns the first (lower) quartile of ...