Average value, with Arithmetic mean ， Geometric mean , mean square (root mean square, rms), Harmonic mean ， weighted average Etc. Among them Arithmetic mean The most common calculation method is:
average value Geometric mean The calculation method of is:
average value It is worth noting that the geometric mean is relative to the Positive number In other words, X1, X2,.. Xn must be positive P. S. Name in Russian: Среднеебначение or Среднеебначение бначение период
Root mean square The calculation method is
average value The calculation method of harmonic average value is N/(1/x1+1/x2+...+1/xn) [1]
weighted average The algorithm is 
average value a. The arithmetic mean of b is (a+b)/2, geometry The average value is ab square root, and the square average value is the average value of the sum of the squares of the three numbers. 
