logo

Ask Questions, Get Answers

 
X
 Search
Want to ask us a question? Click here
Browse Questions
Ad
Home  >>  CBSE XI  >>  Math  >>  Statistics
0 votes

Find the mean and variance of the frequency distribution given below:

$\begin{array}{1 1}(A)\;4.15,3.049\\(B)\;25,1600\\(C)\;790,87\\(D)\;153,45\end{array} $

Can you answer this question?
 
 

1 Answer

0 votes
Toolbox:
  • The formula used to solve this problem are :
  • Mean $(\bar {x} )=\large\frac{\sum f_ix_i}{\sum f_i}$
  • Variance $\sigma^2= \large\frac{\sum f_i (x_i - \bar {x} )^2}{\sum f_i}$
Step 2:
Mean $(\bar {x} )=\large\frac{\sum f_ix_i}{\sum f_i}$
$\qquad= \large\frac{66.5}{16}$$=4.15$
Step 3:
Variance $\sigma^2= \large\frac{\sum f_i (x_i - \bar {x} )^2}{\sum f_i}$
$\qquad= \large\frac{48.785}{16}$
$\qquad= 3.049$
Hence A is the correct answer.
answered Jul 4, 2014 by meena.p
 

Related questions

Ask Question
student study plans
x
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App
...