Question

how do you calculate the standard deviation? 9/13 divide the variance by 2. its a long process and i cant explain it right now. find the mean and multiply it by the variance. take the square root of the variance.

Explanation:

Step1: Recall the relationship between variance and standard - deviation

The standard deviation $\sigma$ of a data - set is related to the variance $\sigma^{2}$. The formula for variance depends on whether it is for a population or a sample. But the key step for getting standard deviation from variance is the same.

Step2: State the calculation step

The standard deviation is the square - root of the variance. That is, if the variance is $s^{2}$ (for a sample) or $\sigma^{2}$ (for a population), then the standard deviation $s=\sqrt{s^{2}}$ (sample) or $\sigma = \sqrt{\sigma^{2}}$ (population).

Answer:

Take the square root of the variance.