WorksheetFunction.Correl Method (Excel)
Returns the correlation coefficient of the Arg1 and Arg2 cell ranges.
Use the correlation coefficient to determine the relationship between two properties. For example, you can examine the relationship between a location's average temperature and the use of air conditioners.
If an array or reference argument contains text, logical values, or empty cells, those values are ignored; however, cells with the value zero are included.
If Arg1 and Arg2 have a different number of data points, Correl generates an error.
If either Arg1 or Arg2 is empty, or if s (the standard deviation) of their values equals zero, Correl generates an error.
The equation for the correlation coefficient is: where x and y are the sample means Average(Arg1) and Average(Arg2).