1. Numerical Variables
Numerical variable (metric variable) is a name that describes the digital characteristics of things, and its value is numerical data. For example, "product output", "commodity sales", "part size", "age" and "time" are all numerical variables, and these variables can take different values. Numerical variables can be divided into discrete variables and continuous variables according to their different values . The characters recognizable in the computer generally correspond to an ASCII code, and the ASCII code is numerical data. When the ASCII code value changes, the corresponding character will also change. Therefore, non-numeric data is essentially numerical data. In order to be close to people's thinking habits and facilitate the writing of programs, the high-level computer language divides the data types: numeric data includes: integer, single- precision, double-precision . Non-numeric data types are: character type or Boolean type or string type .
1.1 Discrete Features of Discrete Variables
Discrete variables refer to variables whose values can be listed one by one in a certain order, usually in integer bits.
The probability distribution of discrete variables, commonly used are binomial distribution and Poisson distribution. There are other probability distributions such as two-point distribution, geometric distribution, and hypergeometric distribution.
1.2 Continuous variables
A variable that can take any value within a certain interval is called a continuous variable, and its value is continuous, and two adjacent values can be infinitely divided, that is, it can take an infinite number of values.
The probability distribution of continuous variables, commonly used are exponential distribution, uniform distribution, normal distribution and so on.
example:
Discrete variable:
1. The number of printing errors in the book.
2. The number of traffic accidents in New Delhi.
3. The number of personal siblings.
Continuous variable:
1. A person's height
2. A person's age
3. The profit earned by the company.