If you specify the keyword CLM, the procedure computes twosided confidence limits for the mean. Also, the procedure includes the confidence limits by default if you do not specify any statistickeywords in the PROC SURVEYMEANS statement.
The confidence coefficient is determined by the value of the ALPHA= option, which by default equals 0.05 and produces 95% confidence limits. The confidence limits are computed as

where is the estimate of the mean, is the standard error of the mean, and is the percentile of the t distribution with df calculated as in the section t Test for the Mean.
If you specify the keyword UCLM, the procedure computes the onesided upper % confidence limit for the mean:

If you specify the keyword LCLM, the procedure computes the onesided lower % confidence limit for the mean:
