Term Overview
Range This can either be presented by giving the minimum and maximum (ie, 100 to 150) or just the amount between (ie, 50).
Population Variance
σ2 = (Σ(x-µ)2)/N
Population Standard Deviation (σ) σ = √σ2
Sample Variance
Sample Standard Deviation
Empirical Rule
Interquartile Range
Interquartile Division
Mean absolute deviation Mean absolute deviation from the mean measures dispersion but not often used. Mathematically better is the sample standard deviation, which is the square root of the sample variance. MAD = [ Σ | X - X | ] / n