Question

Find the mean of the following frequency distribution : 

Class	0-10	10-20	20-30	30-40	40-50	50-60	60-70
Frequency	4	4	7	10	12	8	5

Answer 1

Class Interval	Xi	fi	fixi
0-10	5	4	20
10-20	15	4	60
20-30	25	7	175
30-40	35	10	350
40-50	45	12	540
50-60	55	8	440
60-70	65	5	325
Total		50	1910

`barx =  (Σf_iX_i)/(Σ"f")`

`barx = 1910/50`

`barx = 38.2`

∴ Mean = 38.2