Least Squares Vectorization

Idea:

4b1+3b2=925b1+2b2=808b1+4b2=144(435284)(b1b2)=(9280144)Xb=yXTXb=XTy(XTX)1(XTX)b=(XTX)1XTy(least squares estimator)b=(XTX)1XTy