(d) Describe briefly how this geometrical representation can be used to obtain estimates of ???? and ????2, designated ̂???? and ̂????2.What is the distance from the point y = (y1, y2, y3)′

to the point ̂???? = (̂????, ̂????, ̂????)′?

When this graphical approach is used to represent a sample of two observations, and when any particular values, ̂???? and ̂????2, are postulated for ???? and ????2, the contours of the resulting probability distribution are circles, as shown in Figure 11.5.