Question

Calculate the standard deviation of the following 38, 40, 34, 31, 28, 26, 34

Answer 1

Arrange in ascending order
26, 28, 31, 34, 34, 38, 40
Mean, $\overline{x}=\frac{\sum x}{n}=\frac{231}{7}=33$
$\begin{array}{cccccccc}x& 26& 28& 31& 34& 34& 38& 40\\ x-\overline{x}& -7& -5& -2& 1& 1& 5& 7\\ x-{\overline{x}}^2& 49& 25& 4& 1& 1& 25& 49\end{array}$
${\delta }^2=\frac{\sum (x-\overline{x})x}{=}\frac{154}{7}.22\delta =\sqrt{22}=4.690$