Question

Calculate standard deviation, given the following data:
10, 12, 14, 16, 18, 22, 24, 26, 28

Answer 1

X	$x\mathit{=}\left(\mathit{X}\mathbf{-}\overline{\mathit{X}}\right)$	x2
10 12 14 16 18 22 24 26 28	−8.88 −6.88 −4.88 −2.88 −.88 3.12 5.12 7.12 9.12	78.85 47.33 23.81 8.29 0.77 9.73 26.21 50.69 83.17
∑X = 170		∑x2 = 328.85

$$\begin{gathered} \mathrm{Mean}\left(\overline{X}\right)=\frac{{\sum }_{}X}{N}=\frac{170}{9}=18.88 \\ \mathrm{Standard}\mathrm{Deviation}\left(\mathrm{\sigma }\right)=\sqrt{\frac{{\sum }_{}{x}^2}{N}}=\sqrt{\frac{328.85}{9}}=6.045 \end{gathered}$$