and the estimated value of the standard deviation s by the following calculation:

• the sum of the squares of the measured values: $\sum _{i=1}^{i=n}{\left(x_i\right)}^2$
• the square of the sum of the measured values: ${\left(\sum _{i=1}^{i=n}{x}_i\right)}^2$
  then $\frac{1}{n}{\left(\sum _{i=1}^{i=n}{x}_i\right)}^2$
• the corrected sum $\mathrm{SC}=\sum _{i=1}^{i=n}\frac{\mathrm{SC}={\sum }^{i=n}{\left(x_i\right)}^2-1}{n}{\left(\sum _{i=1}^{i=n}{x}_i\right)}^2$
• the estimated variance: $v=\frac{\mathrm{SC}}{\mathrm{n\; —\; 1}}$

the estimated value of the standard deviation is: $s=\sqrt{v}$