I have two trend-lines, both with a slight negative slope. The first has a greater slope, but significant scatter of the data points, while the second is nearly horizontal with an obvious better fit.
I would typically use an R^2 value to determine fit, but this does not work the closer a line comes to horizontal. Is there an alternate evaluation that assesses the scatter of data on a nearly horizontal line? The data is not meant to be horizontal, so standard deviation would not work either.
