The SAS System Non-Linear Least Squares Iterative Phase Dependent Variable FFE Method: Gauss-Newton Iter E0 EMAX ED50 Sum of Squares 0 5.290000 27.100000 98.100000 12983.695846 1 5.987002 26.534571 105.768660 12947.218827 2 6.027896 26.884407 111.954987 12944.222542 3 6.058424 27.144800 116.401873 12942.843102 4 6.079116 27.320411 119.429021 12942.248810 5 6.092636 27.434586 121.410395 12942.006207 6 6.101248 27.507012 122.672629 12941.910762 7 6.106640 27.552212 123.462484 12941.874112 8 6.109976 27.580129 123.951112 12941.860255 9 6.112026 27.597257 124.251224 12941.855066 10 6.113280 27.607725 124.434731 12941.853136 11 6.114045 27.614105 124.546630 12941.852420 12 6.114510 27.617988 124.614750 12941.852155 13 6.114793 27.620349 124.656177 12941.852057 NOTE: Convergence criterion met. Non-Linear Least Squares Summary Statistics Dependent Variable FFE Source DF Sum of Squares Mean Square Regression 3 53186.147943 17728.715981 Residual 160 12941.852057 80.886575 Uncorrected Total 163 66128.000000 (Corrected Total) 162 26172.760736 Parameter Estimate Asymptotic Asymptotic 95 % Std. Error Confidence Interval Lower Upper E0 6.1147934 1.076788342 3.988220914 8.24136579 EMAX 27.6203494 3.474753757 20.757983552 34.48271529 ED50 124.6561769 47.763214893 30.327577362 218.98477642 Asymptotic Correlation Matrix Corr E0 EMAX ED50 -------------------------------------------------------------- E0 1 -0.193017457 0.3032826797 EMAX -0.193017457 1 0.7834057719 ED50 0.3032826797 0.7834057719 1