Correlation is a measure of the linear relationship between two variables, that is measured on a scale from -1 to 1. The strength of the relationship increases as the correlation moves away from zero.
Correlation and ordinary least squares regression (OLS) are intimately related to one another. OLS is one of several methods available for finding the "best" line to describe a set of points. It has theoretical and computational advantages that make it the most-used method. The result of OLS is a fitted regression line. This line can be found from the means and standard deviations of each variable and the correlation coefficient.
Analyzing data by regression without a computer is very tedious. In an example, we will learn how to pull information from the regression output of a statistics software package.
Bret Larget, larget@mathcs.duq.edu