Which procedure is used to define formats in SAS?

The procedure used to define formats in SAS is PROC FORMAT. This procedure allows users to create and manage custom formats, which can be useful for data presentation and analysis. By using PROC FORMAT, you can specify how data values are displayed in output, making them more readable or meaningful. For example, you can create formats for numeric values to display them with a specific number of decimal places, or you can create categorical formats to replace numeric codes with descriptive labels.

This capability is crucial for enhancing data visualization and making output tables more interpretable. In addition, PROC FORMAT can be used to apply formats across different data steps or procedures, ensuring consistent presentation throughout your SAS programs.

The other options do not serve this specific function: PROC DATA isn't a valid procedure in SAS, PROC SQL is primarily used for querying and manipulating databases, and PROC REPORT is intended for creating reports from data tables without specifically focusing on defining formats.