Question

what is the denominator when calculating the variance and standard deviation for a sample?
○ x
○ x - (overline{x})
○ n
○ n - 1

Explanation:

When calculating sample variance $s^{2}=\frac{\sum_{i = 1}^{n}(x_{i}-\bar{x})^{2}}{n - 1}$ and sample - standard deviation $s=\sqrt{\frac{\sum_{i = 1}^{n}(x_{i}-\bar{x})^{2}}{n - 1}}$, the denominator is $n - 1$ to correct for bias in estimating the population variance from a sample. Here, $n$ is the sample size.

Answer:

$n - 1$