Question

Find the mean deviation about the mean for the data.

xi	5	10	15	20	25
fi	7	4	6	3	5

Options

• 6

• 7.3

• 8

• 6.32

Answer 1

6.32

Explanation:

`bb(x_i)`	`bb(f_i)`	`bb(f_ix_i)`	`bb(|x_i - overlinex|)`	`bb(f_i|x_i - overlinex|)`
5	7	35	9	63
10	4	40	4	16
15	6	90	1	6
20	3	60	6	18
25	5	125	11	55
Total	25	350		158

`overlinex = (sumf_ix_i)/(sumf_i)`

= `350/25`

= 14

Mean deviation from the mean

= `(sumf_i|x_i - overlinex|)/(sumf_i)`

= `158/25`

= 6.32