data _null_; /* set up the width of the desired confidence interval */ ci_alph = .95; obs_a1 = .96; obs_a2 = .95; k1 = 24; k2 = k1; n1 = 286; n2 = 250; if (obs_a1 > obs_a2) then do; /* necessary to reverse everything */ tmp = obs_a1; obs_a1 = obs_a2; obs_a2 = tmp; tmp = k1; k1 = k2; k2 = tmp; tmp = n1; n1 = n2; n2 = tmp; tmp = 1; end; else tmp = 0; w = (1 - obs_a2)/(1 - obs_a1); ci = 100*ci_alph; format ci 2.; df1 = n1 - 1; df2 = n2 - 1; p_null = probf(w,df2,df1); if (tmp = 0) then do; put; put "Given:"; put " Observed alpha 1 = " obs_a1; put " n1 = " n1; put " Observed alpha 2 = " obs_a2; put " n2 = " n2; put " N(items) 1 = " k1; put " N(items) 2 = " k2; put "Probability of difference greater than observed on null"; put " hypothesis of no difference = " p_null; end; else do; put; put "Given:"; put " Observed alpha 1 = " obs_a2; put " n1 = " n2; put " Observed alpha 2 = " obs_a1; put " n2 = " n1; put " N(items) 1 = " k2; put " N(items) 2 = " k1; put "Probability of difference greater than observed on null"; put " hypothesis of no difference = " p_null; end; run;