Division 3.1.4 Calculation of the mean value x — and the estimated standard deviation s of the batch.

Calculate as follows:

• the sum of the 35 actual capacity measurements x = Σx_i

• the mean value of the 35 measurements $\stackrel{—}{x}=\frac{{\mathrm{\Sigma x}}_i}{35}$

• the sum of the squares of the 35 measurements Σx_i ²

• the square of the sum of the 35 measurements (Σx_i)², then $\frac{{\left({\mathrm{\Sigma x}}_i\right)}^2}{35}$

• the corrected sum: $\mathrm{SC\; =\; \Sigma }{x_i}^2—\frac{1}{35}{\left({\mathrm{\Sigma \; x}}_i\right)}^2$

• the estimated variance $\mathrm{v\; =}\frac{\mathrm{SC}}{34}$

Hence the estimated standard deviation: $\mathrm{s\; =}\sqrt{v}$