Which statement is used to summarize group data in PROC MEANS?

To summarize group data in PROC MEANS, the CLASS statement is utilized. This statement allows you to define one or more categorical variables that will be used to group the data, enabling the PROC MEANS procedure to calculate summary statistics such as means, sums, and counts for each level of the specified categorical variables.

When a CLASS statement is included, PROC MEANS will generate output that reflects those groupings, thus offering a means to analyze and report on different segments of the dataset. This is particularly useful for comparing statistics across different categories within the data.

For instance, if you have a dataset containing sales information for various products across different regions, employing the CLASS statement with the region variable would allow you to see the average sales per region, providing clear insights from the data.

The other options, while related to data manipulation and summarization, do not specifically function to create group summaries in PROC MEANS. The GROUP BY approach is often associated with SQL procedures, SORT organizes data but does not summarizae, and SUMMARY is not a valid statement in PROC MEANS context. Thus, the CLASS statement is the correct choice for summarizing group data when using PROC MEANS.