I am attempting to use SAS 9.4 to generate confidence intervals for basic descriptive statistics (means, medians, relative frequencies) in the U.S. Census Bureau's Current Population Survey. I have downloaded the replicate weight files, and have been using the following code, for example, to derive a confidence interval for the variable "nchild."   proc surveymeans median data = temp varmethod = jackknife; weight wtsupp; repweights repwt1 -- repwt160; var nchild; run;   However, when I do so, I end up with very wide confidence intervals e.g. a percentage CI of 4.8-15.1% in a cell with 840 unweighted observations. Has anybody else used the replicate weights to generate confidence intervals, and have you calculated similarly wide intervals? Or am I misinterpreting how to use the replicate weights?    Thanks! ... View more