Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • School
  • If the mean of the following frequency distribution is 62·8, then find the missing frequency x : Class</str

If the mean of the following frequency distribution is 62·8, then find the missing frequency x :

Class 0-20 20-40 40-60 60-80 80-100 100-120
Frequency 5 8 x 12 7 8

 

 

 

 

 
 
 
 
 

Answers (1)

Class Frequency (f_i) x_i

f_ix_i
0-20 5 10 50
20-40 8 30 240
40-60 x 50 50x
60-80 12 70 840
80-100 7 90 630
100-120 8 110 880

\sum f_i = 40+x

\sum f_ix_i = 2640 + 50x

By direct method :

\text{Mean}=\frac{\sum f_ix_i}{\sum f_i}

62.8 =\frac{2640+50x}{40+x}

62.8(40+x) =2640+50x

2512 + 62.8 x =2640+50x

62.8 x - 50x = 2640-2512

12.8 x = 128

x = 10

Therefore, the missing frequency is 10.

Posted by

Ravindra Pindel

View full answer

Similar Questions

Trending Articles/News

anam-khan

CBSE Curriculum 2026-27: Three-language policy is ‘compulsory Hindi’, says Tamil Nadu CM; criticism online
anam-khan

CBSE Board Class 10 Result LIVE: When are CBSE 10th results coming to results.cbse.nic.in? 2nd exams schedule
anam-khan

CBSE changing Class 9, 10 syllabus from 2026-27; 3rd language compulsory, 2 levels of maths, science

Latest Question