The SURVEYMEANS Procedure
When you specify the keyword MEAN, the procedure computes the estimate of the mean (mean per element) from the survey data. Also, the procedure computes the mean by default if you do not specify any statistic-keywords in the PROC SURVEYMEANS statement.
PROC SURVEYMEANS computes the estimate of the mean as
![\[ \widehat{\bar{Y}} = \left( \sum _{h=1}^ H\sum _{i=1}^{n_ h} \sum _{j=1}^{m_{hi}} ~ w_{hij} ~ y_{hij} \right) / ~ w_{\cdot \cdot \cdot } \]](images/statug_surveymeans0044.png){kind=small}
where
![\[ w_{\cdot \cdot \cdot } = \sum _{h=1}^ H\sum _{i=1}^{n_ h} \sum _{j=1}^{m_{hi}} w_{hij} \]](images/statug_surveymeans0045.png){kind=small}
is the sum of the weights over all observations in the sample.