The SAS System The LOGISTIC Procedure Model Information Data Set WORK.GRAVITY Response Variable (Events) r Response Variable (Trials) n Model binary logit Optimization Technique Fisher's scoring Number of Observations Read 6 Number of Observations Used 6 Sum of Frequencies Read 166 Sum of Frequencies Used 166 Response Profile Ordered Binary Total Value Outcome Frequency 1 Event 70 2 Nonevent 96 Model Convergence Status Convergence criterion (GCONV=1E-8) satisfied. Model Fit Statistics Intercept Intercept and Criterion Only Covariates AIC 228.036 187.859 SC 231.148 194.083 -2 Log L 226.036 183.859 Testing Global Null Hypothesis: BETA=0 Test Chi-Square DF Pr > ChiSq Likelihood Ratio 42.1765 1 <.0001 Score 37.8303 1 <.0001 Wald 31.1219 1 <.0001 The SAS System The LOGISTIC Procedure Analysis of Maximum Likelihood Estimates Standard Wald Parameter DF Estimate Error Chi-Square Pr > ChiSq Intercept 1 -2.8155 0.5048 31.1055 <.0001 gravity 1 0.7998 0.1434 31.1219 <.0001 Odds Ratio Estimates Point 95% Wald Effect Estimate Confidence Limits gravity 2.225 1.680 2.947 Association of Predicted Probabilities and Observed Responses Percent Concordant 69.8 Somers' D 0.549 Percent Discordant 15.0 Gamma 0.647 Percent Tied 15.2 Tau-a 0.269 Pairs 6720 c 0.774 The SAS System Obs gravity r n phat lcl ucl 1 0 0 10 0.05649 0.02178 0.13871 2 1 2 25 0.11756 0.06012 0.21719 3 2 10 28 0.22864 0.15170 0.32945 4 3 13 31 0.39742 0.31490 0.48622 5 4 20 43 0.59473 0.49485 0.68733 6 5 25 29 0.76554 0.64295 0.85550