The most mathematically sound method is to find the covariance for the two variables and the standard deviations of each variable, then use the following formula: Correlation Coefficient=COVSDMI ...

The correlation coefficient always returns a value ... then use the following formula: Finding the covariance and standard deviation for each variable can be a lengthy, involved process.

This example does not examine the correlation matrix but assumes that all items are positively correlated. Normally, you want to examine the correlation and covariance matrices to make sure that all .