Find the mean of each of the following frequency distributions :

Let the assumed mean be A = 25 and h = 10.

We know that mean, $\bar{X}=A+h\left(\frac{1}{N} \sum f_{i} u_{i}\right)$

Now, we have $N=\sum f_{i}=60, \sum f_{i} u_{i}=8, h=10$ and $A=25$.

Putting the values in the above formula, we have

$\bar{X}=A+h\left(\frac{1}{N} \sum f_{i} u_{i}\right)$

$=25+10\left(\frac{1}{60} \times(8)\right)$

$=25+\frac{80}{60}$

$=25+1.333$

$=26.333$

Hence, the mean is 26.333.