### Confidence Limits for the Mean

If you specify the keyword CLM, the procedure computes two-sided confidence limits for the mean. Also, the procedure includes the confidence limits by default if you do not specify any *statistic-keywords* 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 th percentile of the *t* distribution with *df* calculated as described in the section *t* Test for the Mean.

If you specify the keyword UCLM, the procedure computes the one-sided upper % confidence limit for the mean:

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

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