Question

Find the mean of the following data: Class 0–20 20–40 40–60 60–80 80–100 Frequency 5 15 30 8 2

Answer 1

Answer:

Answer is 53

Step-by-step

Calculation of Mean

0-20 10 15 -40 -2 -30

20-40 30 18 -20 -1 -18

40-60 50 21 0 0 0

60-80 70 29 20 1 29

80-100 90 17 40 2 34

∑f  

i

​  

=100   ∑f  

i

​  

u  

i

​  

=15

We have,

A= 50, h= 20, N= 100 and ∑f  

i

​  

u  

i

​  

=15

∴Mean=A+h[  

N

1

​  

∑f  

i

​  

u  

i

​  

]

⇒Mean=50+20×  

100

15

​  

 

$$\Rightarrow  Mean = 50+3= 53