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 \begin{aligned} &\sum X^{2}=1^{2}+2^{2}+4^{2}+5^{2}=46 \\ &\frac{\left(\sum X\right)^{2}}{N}=\frac{(1+2+4+5)^{2}}{4}=\frac{144}{4}=36 \\ &\sigma^{2}=\frac{(46-36)}{4}=2.5 \\ &s^{2}=\frac{(46-36)}{3}=3.333 \text { as with the other formula } \end{aligned}