1, continuous variables are always superimposed, and the amount of growth can be divided into fixed units, that is, 1, 2,3. For example, a person's height first increases to 1.7 1, and then to 1.72,/kloc-0.

2. Discrete variables are obtained by counting, that is, counting the objects to be counted, and the amount of growth is not fixed. For example, the number of enterprises in a region can be only one this year, and ten enterprises will be opened in the second year; The number of employees in an enterprise is only 10 this year, and 20 employees were recruited in the second year. ?

3. For discrete variables, if the variation range of variable values is small, a variable value can correspond to a group, which is called single grouping. If families are grouped according to the number of children or population, the single grouping method can be used.

4. Discrete variables If the variable value changes greatly and there are multiple variable values, the whole variable value is divided into several intervals in turn, and each variable value is determined according to its size. The distance between intervals is called group distance, and such grouping is called group distance grouping.

What are the demographic variables?

1, gender, age, health status.

2. Occupation, marriage, education level and income.