PROC SURVEYMEANS: Confidence Limits for the Mean

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

$\text{[math]}$

where $\text{[math]}$ is the estimate of the mean, $\text{[math]}$ is the standard error of the mean, and $\text{[math]}$ is the $\text{[math]}$ 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 $\text{[math]}$ % confidence limit for the mean:

$\text{[math]}$

If you specify the keyword LCLM, the procedure computes the one-sided lower $\text{[math]}$ % confidence limit for the mean:

$\text{[math]}$

The SURVEYMEANS Procedure

Confidence Limits for the Mean