Q15 of 46 Page 278

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

Given: the frequency distribution


To find: the mean and variance


Converting the ranges of x to groups, the given table can be rewritten as shown below,



And we know variance can be written as



Substituting values from above table, we get





We also know mean can be written as



Substituting values from above table, we get



Hence the mean and variance of the given frequency distribution is 4.16 and 3.96 respectively.


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