Lesson Plan

Define a residual as observed minus predicted and compute residuals for data points

Construct a residual plot (residual versus x) with a reference line at zero

Interpret a residual plot - random scatter signals a good fit, a pattern signals the wrong model

Decide, from the residual plot, whether to keep the fitted model or refit with a different function family

HSS.ID.B.6.b

HSS.ID.B.6.b: Informally assess the fit of a function by plotting and analyzing residuals.