Variance

The population variance is the average of the squared deviations from the mean. The sample variance is the sum of the squared deviations from the mean divided by one less than the number of data values.

Population Variance (image\popvar-sym.png

image\popvar.png

Sample Variance (s2)

image\samvar.png

where

image\u.png

= Population Mean

image\mean.png

= Sample Mean

N

= number of data values (for a population)

n

= number of data values (for a sample)

xi

= ith data value

See Also

Data Statistics

95% and 99% Confidence Interval for the Mean

Average Deviation

Coefficient of Kurtosis

Coefficient of Skewness

Coefficient of Variation

Critical Value of K-S Statistic at 90%, 95%, and 99% Significance Level

Kolmogorov-Smirnov Goodness of Fit Statistic for Normal Distribution

Mean

Standard Deviation

Standard Error of the Mean

Statistics References