Statistical Analysis System (SAS) Programming Certification Practice Exam

Which statement limits a PROC MEANS analysis to specific variables?

1. by boarded transfer deplane;

2. class boarded transfer deplane;

3. output boarded transfer deplane;

4. var boarded transfer deplane;

The correct answer is: var boarded transfer deplane;

In SAS programming, the PROC MEANS procedure is used to calculate descriptive statistics for specified variables within a dataset. To focus the analysis on particular variables, the VAR statement is utilized. The VAR statement explicitly lists the variables you wish to analyze, allowing you to control which aspects of the data you want to investigate. When you use the VAR statement followed by one or more variable names, such as "boarded," "transfer," and "deplane," PROC MEANS will compute statistics only for these specified variables. This capability is crucial for targeted analysis, enabling you to derive specific insights without clutter from unrelated data. The other statements have different functions: - The BY statement group the data for analysis before calculations are performed but does not limit specific variables for statistical calculations. - The CLASS statement categorizes data into groups for statistics but again does not restrict the analysis to specific variables. - The OUTPUT statement is used to create a new dataset containing the results of the analysis, but it does not itself limit the variables used for computation. Thus, the use of the VAR statement effectively narrows down the analysis in PROC MEANS to only those variables listed, making it the correct choice.