In a study of the regression of Y on X in three groups, some of the results were = 72.56; = 80.63; = 90.06; = 56.71; = 68.09; and = 75.42. The SUbscripts refer to groups 1, 2, and 3 respectively....

In a study of the regression of Y on X in three groups, some of the results were

= 72.56;

= 80.63;
= 90.06;

= 56.71;

= 68.09; and

= 75.42. The SUbscripts refer to groups 1, 2, and 3 respectively. Using these data calculate the following:

(a) The three separate b's.

(b) The common b.

(c) The regression sum of squares when the separate b's are used.

(d) The regression sum of squares when the common b is used.