Enter a comma- or space-separated list of numbers to compute the sample variance s2 = sum(x - xbar)2 / (n - 1), the squared standard deviation used in statistical description and ANOVA.
输入多个数值（逗号或空格分隔），求样本方差。
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Sample variance | s^2 = sum(x_i - xbar)^2 / (n - 1) | ISO 3534-1:2006, Statistics - Vocabulary and symbols |
| Computational form | s^2 = ( sum x_i^2 - (sum x_i)^2 / n ) / (n - 1) | NIST/SEMATECH e-Handbook of Statistical Methods §1.3.5.1 |
| Role in ANOVA | ANOVA decomposes total variation into within-group and between-group variance via an F ratio | Fisher RA, Statistical Methods for Research Workers (1925) |
| Relation to standard deviation | s = sqrt(s^2), restoring the unit of the original data | ISO 3534-1:2006, Statistics - Vocabulary and symbols |