How can the correlation between two variables be calculated in SAS?

The most effective way to calculate the correlation between two variables in SAS is through PROC CORR. This procedure specifically focuses on analyzing the strength and direction of the linear relationship between multiple variables. When you use PROC CORR, it computes the correlation coefficients, such as Pearson's correlation, allowing you to assess how closely related the two variables are.

PROC CORR provides not only the correlation coefficients but also relevant statistics that can help in understanding the data distribution and relationships. This procedure is designed for these types of analyses, making it the most suitable and straightforward option for calculating correlations.

The other methods mentioned are not appropriate for calculating correlation coefficients. For instance, PROC MEANS is primarily used for summarizing data and does not provide direct correlation measures. PROC REG is used for regression analysis, focusing instead on modeling relationships rather than simply measuring correlation. Finally, while simple arithmetic calculations might involve finding differences or summations, they lack the statistical rigor and methods necessary to derive a correlation coefficient accurately. Thus, PROC CORR remains the optimal choice for this purpose.