Question:
For the frequency distribution:
Find the standard distribution.
Solution:
Given frequency distribution table
Now we have to find the standard deviation
Let us make a table of the given data and append other columns after calculations
And we know standard deviation is
$\sigma=\sqrt{\frac{\sum f_{i} x_{i}^{2}}{n}-\left(\frac{\sum f_{i} x_{i}}{n}\right)^{2}}$
Substituting values from above table, we get
$\sigma=\sqrt{\frac{1393}{60}-\left(\frac{277}{60}\right)^{2}}$
$\sigma=\sqrt{23.23-(4.62)^{2}}$
$\sigma=\sqrt{23.23-21.34}$
$\Rightarrow \sigma=1.37$
Hence the standard deviation is $1.37 .$