For example, the mathematical model of multiple linear regression can be expressed as y=β0+β 1*x+εi, where β0, β 1, …, βp are the parameters to be estimated, εi is a random variable that is independent of each other and obeys the same normal distribution N(0, σ2), and Y is a random variable. X can be a random variable or a non-random variable, and βi is called the regression coefficient, indicating the degree of influence of independent variables on dependent variables.