/** * Trimean (TM, or Tukey's trimean) * A measure of a probability distribution's location defined as * a weighted average of the distribution's median and its two quartiles. * https://en.wikipedia.org/wiki/Trimean * * Q₁ + 2Q₂ + Q₃ * TM = ------------- * 4 * * @param array $numbers * @return number */ public static function trimean(array $numbers) { $quartiles = Descriptive::quartiles($numbers); $Q₁ = $quartiles['Q1']; $Q₂ = $quartiles['Q2']; $Q₃ = $quartiles['Q3']; return ($Q₁ + 2 * $Q₂ + $Q₃) / 4; }