If the data x _ 1 , x _ 2 , x _ 10 is such that the mean of first...

Let the numbers are ${x}_{1}, {x}_{2}, \ldots {x}_{10}\left(N = 10\right)$
Given \left$$\begin{array}{ll}{x}_{1} + {x}_{2} + {x}_{3} + {x}_{4} = 4.11 = 44 \\ {x}_{5} + {x}_{6} \ldots . + {x}_{10} = 6.16 = 96\end{array}$$\right\} ⇒ ∑ {x}_{i} = 140$<br />$⇒$variance${\sigma}^{2} = \dfrac{∑ {x}_{i}^{2}}{N} - {\left(\dfrac{∑ {x}_{i}}{N}\right)}^{2}$<br />$⇒ {\sigma}^{2} = \dfrac{2000}{10} - {\left(\dfrac{140}{10}\right)}^{2}$<br />$⇒ {\sigma}^{2} = 200 - 196 = 4$<br />$⇒$Standard deviation$\sigma = 2 .