Math Studies students learn to draw lines of fit by hand through correlated data. They also learn how to calculate the regression line (line of best fit), though in practice this would be done by a calculator or spreadsheet program. Once obtained, a line of fit can be used to make predictions about missing data (interpolation) or predictions extending beyond the data (extrapolation).
When you see Willem, ask him whether interpolation is more or less accurate than extrapolation for strongly correlated data.
