1. Sometimes the conditions of the problem dictate that the intercept coefficient Bo must be zero. This is called regression through the origin. (a) Show that the least square estimate of the slope coefficient B1 when fitting the straight line y = Bix based on the data (x1, y1), (x2, 92), . .., (Xn, Un) is B1 = Lizliyi (b) Suppose that the following generative model for your dataset holds: Yi = Bixitci, ci~ N(0, 02), for i = 1, ..., n. Derive the sampling distribution of B1