Question

Find the mean deviation about the mean for the data

xi	10	30	50	70	90
fi	4	24	28	16	8

Answer 1

xi	fi	fi xi
10	4	40	40	160
30	24	720	20	480
50	28	1400	0	0
70	16	1120	20	320
90	8	720	40	320
	80	4000		1280