Consider the simple linear regression model: y = ax + b. Given (x1, y1), (x2, y2), ..., (xm, ym), please verify that the optimal solution is given by:
a) a = Σxy / Σx² and b = (Σy - aΣx) / m
b) a = Σx / Σy and b = (Σy - aΣx) / m
c) a = Σxy / Σy² and b = (Σy - aΣx) / m
d) a = Σx² / Σxy and b = (Σy - aΣx) / m