3-10 Determining the regression Coefficients So how do we determine what a and B are? Choose a and B so that the(vertical) distances from the data points to the fitted lines are minimised(so that the line fits the data as closely as possible)3-10 Determining the Regression Coefficients • So how do we determine what  and  are? • Choose  and  so that the (vertical) distances from the data points to the fitted lines are minimised (so that the line fits the data as closely as possible): y x