1. The determinable coefficient is high, which can be regarded as high fitting.
2. Through the t test of explanatory variables, it is found that x 1x3 has a significant influence on explanatory variables, while others are not. The F test of the equation passed, so the equation was significant. So variables are multiple * * * linear. I don't know the specific topic, assuming that your explanation of the economic significance of variable coefficient is correct.
3. Regression between Y and x 1x2x3x4, find out the initial regression model, and then gradually find out the adjusted regression equation.
(a little personal opinion)