The n-th root of the product of n observations defining the sum formula is the geometric mean. According to different data conditions, geometric mean can be divided into weighted and unweighted.

Let a set of data be X 1, X2, ..., Xn, and greater than 0, then the arithmetic mean is:

Xg=n√x 1*x2*...Xn The calculation of geometric mean of main purpose needs to observe the continuous product relationship between values, and its main purpose is:

1, average ratio, index, etc. 2. Calculate the average development speed;