Gotcha, I don't think I know enough about it. What constitutes training data for a for a (non neural network) statistical model? Is this something I could play around with myself with pen and paper?
Just the raw numbers? You list the y's and the x's and the model is approximating y=f(x) from the above example. You can totally do it with pen and paper.
This is what it'd look like (for linear regression): https://observablehq.com/@yizhe-ang/interactive-visualizatio...