sniffed around for a simple explanation of a "regression analysis" for myself and others who may not fully understand it.......this answer is (maybe) simplistic but gets the point across IMO. GL, cheapie

Regression is trying to take a group of data points and figuring out what equation(s) satisfy those data points.

For example, say I wanted to try to figure out an equation that dictated a certain stocks performance. I could take the closing price of that stock for every day in the last year. I then would be trying to figure out what equation satisfies all those points. The equation could then be used to try to predict future performance.

The same thing could be done with temperature. I could chart the average temperature for the last 100 years at a location. Regression would then be trying to find the equation that satisfies all the temperatures. The equation could then be used to predict future temps.