Question

For the given frequency distribution, find the:

1. mean, to the nearest whole number
2. median

x	10	11	12	13	14	15	16
f	3	2	2	6	3	5	3

Answer 1

(a)

x	f	fx	cf
10	3	30	3
11	2	22	5
12	2	24	7
13	6	78	13
14	3	42	16
15	5	75	21
16	3	48	24
	`bb(sumf = 24)`	`bb(sumfx = 319)`

Mean = `(sumfx)/(sumf)`

`319/24`

= 13.29

= 13

(b) Here, N = 24, which is even

Median = `((n^(th))/2 "observation" + (n/2 + 1)^(th) "observation")/2`

= `(12^(th) "observation" + 13^(th) "observation")/2`

= `(13 + 13)/2`

= `26/2`

= 13