Sample/Population Standard Deviation Calculator

Calculate standard deviation step by step

For the given set of observations, the calculator will find their standard deviation (either sample or population), with steps shown.

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Your Input

Find the sample standard deviation of 11, 3737, 99, 00, 35- \frac{3}{5}, 99, 1010.

Solution

The sample standard deviation of data is given by the formula s=i=1n(xiμ)2n1s = \sqrt{\frac{\sum_{i=1}^{n} \left(x_{i} - \mu\right)^{2}}{n - 1}}, where nn is the number of values, xi,i=1..nx_i, i=\overline{1..n} are the values themselves, and μ\mu is the mean of the values.

Actually, it is the square root of variance.

The mean of the data is μ=32735\mu = \frac{327}{35} (for calculating it, see mean calculator).

Since we have nn points, n=7n = 7.

The sum of (xiμ)2\left(x_{i} - \mu\right)^{2} is (132735)2+(3732735)2+(932735)2+(032735)2+(3532735)2+(932735)2+(1032735)2=178734175.\left(1 - \frac{327}{35}\right)^{2} + \left(37 - \frac{327}{35}\right)^{2} + \left(9 - \frac{327}{35}\right)^{2} + \left(0 - \frac{327}{35}\right)^{2} + \left(- \frac{3}{5} - \frac{327}{35}\right)^{2} + \left(9 - \frac{327}{35}\right)^{2} + \left(10 - \frac{327}{35}\right)^{2} = \frac{178734}{175}.

Thus, i=1n(xiμ)2n1=1787341756=29789175\frac{\sum_{i=1}^{n} \left(x_{i} - \mu\right)^{2}}{n - 1} = \frac{\frac{178734}{175}}{6} = \frac{29789}{175}.

Finally, s=i=1n(xiμ)2n1=29789175=20852335s = \sqrt{\frac{\sum_{i=1}^{n} \left(x_{i} - \mu\right)^{2}}{n - 1}} = \sqrt{\frac{29789}{175}} = \frac{\sqrt{208523}}{35}.

Answer

The sample standard deviation is s=2085233513.04694819269461s = \frac{\sqrt{208523}}{35}\approx 13.04694819269461A.