One is expressed by absolute number (frequency).

The second is expressed by relative number (frequency).

Theoretically, the weight determines the structure of the index. If the weight changes, the absolute index value and average value will also change, so the weight is an important factor affecting the change of index value. The balance function of weight is to reflect the proportion of each group of units to the total number of units, which is widely used to calculate the average and index.

Weight can be in the form of price, cost, output or sales volume of a group of different products, or in the form of value of a group of products or other totals. In addition, the weight can also take the form of proportion, for example, the price of various commodities is weighted by the proportion of the sales of a certain kind of goods to the total sales, so as to calculate the price index. Which form of weight is adopted mainly depends on the data form and calculation method selected when calculating the index.

The average value depends not only on the tag value (variable value) of each cell in the population, but also on the frequency of each tag value. Because the frequency of each sign value plays a role in measuring its influence in the average, it is called weight. In weighted arithmetic, the sum of the weights of each variable is equal to 1, and the weights of different variables can be set as needed.

Extended data:

The weight determines the structure of the index. If the weight changes, the absolute index value and average value will also change, so the weight is an important factor affecting the change of index value. Weight is generally expressed in two forms: one is absolute number (frequency) and the other is relative number (frequency).

Relative number is expressed as a percentage (%) or one thousandth (‰) of absolute number, also called specific gravity. The size of the average depends not only on the tag value (variable value) of each unit in the group, which shows that the weighting function of the weight reflects the proportion of each group of units to the total number of units.

For example, the weight in industrial production index is an index that defines the importance of a single index of products in the formation of production index. Different importance of products has different effects on development speed. The product or industry accounts for a large proportion, the weight is large, and the role in the index is great.

The weight in the comprehensive index of industrial economic benefits is determined according to the importance of each index in the comprehensive economic benefits. Retail price index not only uses representative specifications to calculate individual price index, but also uses retail sales as weight to weigh the importance of individual commodity price index in the formation of total price index.

References:

Baidu encyclopedia-weight