What is the reason for using group median to represent the general level of variable value in group interval sequence?

What is the reason for using group median to represent the general level of variable value in group interval sequence?

When calculating the arithmetic mean with group interval variable sequence, the group median represents the general level of variables in the group. There is a hypothesis that the values of variables in each group are evenly distributed in the group

What are the two elements of variable sequence?

The concept of variable sequence
On the basis of grouping the whole population, the units of the whole population are grouped and arranged to form the distribution of the units of the whole population among the groups, which is called statistical distribution. The essence of statistical distribution is the number sequence formed by distributing all the units of the whole population according to the groups of a certain mark, so it is also called distribution sequence or distribution sequence
The distributive sequence consists of two elements: the group of a population according to a sign and the number of units distributed by each group
Statistical distribution is an important form of statistical collation results. It can show the distribution characteristics and structure of the overall unit among each group. On this basis, we can further study the composition, average level and change law of the indicators
According to different grouping marks, the allocation sequence is divided into quality allocation sequence and variable allocation sequence
The distribution sequence compiled by grouping according to quality marks is called quality distribution sequence, also referred to as quality sequence. It is mainly used to reflect the structure, proportional relationship and distribution law of social and economic phenomena

What are the two elements of statistical distribution sequence?

Statistical distribution is to arrange all the units of the population in groups on the basis of statistical grouping. It forms the distribution of each unit in the population among groups. Its essence is to distribute all the units of the population in groups according to a certain mark to form a series, so it is also called distribution series or distribution series. Statistical distribution consists of two components: the group of the population according to a certain mark, According to the different grouping marks, the allocation sequence is divided into quality allocation sequence and variable allocation sequence