Results of Excel® Solver optimization for different prediction equations with and without error weighting.

Prediction equation		X	Y	Mean squared error
Weighted errors	k rel = drelxρrely	0.03288	0.43578	0.03179
	k rel = drelx	0.12835	—	0.43044
	k rel = ρrely	—	0.54263	0.06549
Unweighted errors	k rel = drelxρrely	0.03472	0.42473	0.04787
	k rel = drelx	0.13658	—	0.52388
	k rel = ρrely	—	0.52914	0.08776