Question

Calculate arithmetic mean of the following frequency distribution :
Class : less than 10, 10-20,20-30,30-40,40-50,50-60, more than 60

Frequency: 5,12,18,22,6,4,3

Answer 1

Explanation:

class frequency X fx

(f)

0-10 5 5 25

10-20 12 15 180

20-30 18 25 450

30-40 22 35 770

40-50 6 45 270

50-60 4 55 220

60-70 3 65 195

70 2110

Mean = fx/x

= 2110/70 = 30.14

mean is 30.14