nag_step_regsn (g02eec) Example Program Results Step 1 Added variable is TS Change in residual sum of squares = 4.7126e-01 F Statistic = 7.38 Variables in model: COD TS Residual sum of squares = 1.0850e+00 Degrees of freedom = 17 Free variables: TKN BOD TVS Change in residual sums of squares for free variables: 0.1175 0.0600 0.2276 Step 2 No further variables added maximum F = 1.59 Free variables: TKN BOD TVS Change in residual sums of squares for free variables: 0.0979 0.0207 0.0217