Average, MeanExpectation operator is lineark-th moment of Xdefined as the expected value of x raised to the power of kIf only X, Y is independence, does not means Expectation value NotionLaw of total expectationThe law of Large number AveragesArithmetic MeanGeometric AveragePolyak averageHarmonic Mean Harmonic Mean, Arithmetic Mean and Harmonic Mean are Pythagorean meansPythagorean meansIn mathematics, the three classical Pythagorean means are the arithmetic mean (AM), the geometric mean (GM), and the harmonic mean (HM). These means were studied with proportions by Pythagoreans and later generations of Greek mathematicians because of their importance in geometry and music.https://en.wikipedia.org/wiki/Pythagorean_means