Find the standard deviation for the following data:
 

 

     $$\begin{gathered} From the table N= \sum _{ }^{ }{f}_i=48 \\ and \sum _{ }^{ }{f}_i{x}_i=614 \end{gathered}$$

$\begin{array}{r}\text{ Now, }\sigma =\frac{1}{N}\sqrt{N\sum f_i{x}_i^2-{\left(\sum f_i{x}_i\right)}^2}\\ =\frac{1}{48}\sqrt{48\times 9652-(614{)}^2}\\ =\frac{1}{48}\times 293.77=6.12\end{array}$