The ancient meaning of "force" is weight, which is an iron knot that can slide on the scale to observe the quality. "Mencius Hui Liang Wang Shangshang" said: "Powerful people know the weight." That's what it means.

1. In daily life, we often use the average value to represent the' average level' of a set of data.

2. In a set of data, the number of times a data appears is called weight. It is the "proportion" or "share" of the observed values with unequal precision when calculating the most reliable value of the unknown quantity.

It can show the importance of numbers in mathematics and is widely used in graph theory. Such as the shortest path with weight.