Question:
If $\sum_{\mathrm{i}=1}^{9}\left(\mathrm{x}_{\mathrm{i}}-5\right)=9$ and $\sum_{\mathrm{i}=1}^{9}\left(\mathrm{x}_{\mathrm{i}}-5\right)^{2}=45$, then the standard deviation of the 9 items $\mathrm{x}_{1}, \mathrm{x}_{2}, \ldots . . \mathrm{x}_{9}$ is
Correct Option: , 2
Solution:
