I want to calculate 95% CI for proportion/percentage for a dataset as the following. Original dataset a, I would like to have an output dataset b as such. I have tried some program but not sure if it was correct. Do you have different ways to calculate the 95% CI? Thanks for helping in advance.    Dataset a Disease   cases   Denominator   proportion A              2           120                 0.167 B              5           300                 0.167 C              3           1000               0.3 D             11           500                0.2   Dataset B Disease   cases   Denominator   proportion   CI_low  CI_high A              2           120                 0.167 B              5           300                 0.167 C              3           1000               0.3 D             11           500                0.2   SAS program I tried:    data b; set a; p=(cases/denominator); if p=0 then CI_Low=0; if p=1 then CI_High=1; if p ne 0 then CI_Low=(1-betainv(.975, (Denominator-cases+1), cases)); if p ne 1 then CI_High=(1-betainv(.025, (Denominator-cases), cases+1); run;   ... View more