Let x1 7, x2 2, x3 4, x4 7, y1 5, y2 2, y3 3, y4 12.

Let x1 ¼ 7, x2 ¼ 2, x3 ¼ 4, x4 ¼ 7, y1 ¼ 5, y2 ¼ 2, y3 ¼ 3, y4 ¼ 12.

Calculate the following:

(a) x; i=1 x/4 (b) x=x 4 i=1 (c)(x-5) (d)(x-5) [Note: I is called the arithmetic average or arithmetic mean.] (e) (x)(y-y) where y= 4 xiyi - 4 xxx y (f) 4 IM+ =1/4 -4 xx