KnowraLaw of total varianceLinked fromLinked fromThe 3 pages that link to Law of total variance, each with the reason it gives.All 3Broader topic 1Related 2VarianceBroader topic: It separates within-group spread from variation between group means.Law of total probabilityRelated: It applies the same conditioning strategy to quantify uncertainty.Rao–Blackwell theoremRelated: It explains why conditioning cannot increase variance.