Number sets have variance spread {dispersion, statistics}|. Dispersion is torques of numbers around balance point: sum from i = 1 to i = N of (n(i) - x)^2 / N, or sum from i = 1 to i = N of (n(i))^2 / N - x^2, where n(i) are numbers, and x equals mean.
Fourth moment {kurtosis, distribution} measures distribution fatness or slimness.
Square root of mean of squares of differences between numbers and mean {root mean square} (RMS) can equal standard deviation.
Third moment {skewness, distribution} measures distribution asymmetry, whether it is more to right or left of mean. Skew distribution is not symmetric. To find skewness, calculate median and compare to mean.
Sample-mean distribution standard deviation {standard error of the mean}| is smaller than population standard deviation: s / N^0.5, where s is population standard deviation, and N is sample size.
Variance has a square root {standard deviation}|.
Torques of numbers around balance point measure dispersion {variance, distribution}|: sum from i = 1 to i = N of (n(i) - x)^2 / N, or sum from i = 1 to i = N of (n(i))^2 / N - x^2, where n(i) are numbers, and x equals mean.
3-Statistics-Statistical Population-Statistic
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225