📈 Residual Plots and Fit Signals

Using their phase 3 datasets in Desmos or a spreadsheet, students examine side-by-side linear, exponential, and logarithmic fits and learn how residual plots, scale, and transformed views reveal model quality. The instructor models one case with explicit attention to parameter meaning, domain restrictions, and when a strong-looking graph is still a weak contextual model. Students annotate one worked example in their notebook with a short claim about which representation gives the strongest evidence.