What is a histogram used for in the PROC UNIVARIATE process?

A histogram is a graphical representation that is used to display the distribution of a continuous variable. In the context of the PROC UNIVARIATE process in SAS, the histogram is particularly useful for visualizing the frequency of different ranges of values, enabling analysts to see the shape of the data’s distribution, identify any skewness, modality, or potential outliers.

When working with datasets in clinical trials, understanding the distribution of key variables, such as patient outcomes or measurements, is essential for statistical analysis. The ability to visually assess how data is spread out and where values cluster can help guide further analysis and decision-making in a clinical setting. Thus, option A accurately describes the purpose of a histogram within PROC UNIVARIATE.

The other options relate to different data analysis techniques and visualizations. Summarizing categorical data involves different statistical measures, while showing correlation pertains to bivariate analysis often represented through scatterplots or correlation matrices. Analyzing time-to-event data typically involves survival analysis and specialized graphs, which do not include histograms as a primary tool.