# Dispersion

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 σ ^{2} |
σ^{2} = (Σ(x-µ)^{2})/N |

Population Standard Deviation (σ) | σ = √σ^{2} |

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 |