Regular regression coefficients describe the relationship between each predictor variable and the response. The coefficient value represents the mean change in the response given a one-unit increase in the predictor.
For each predictor variable (X1, X2, X3) describe what the expected direction of the relationship between each X and the criterion or Y variable would be. For example if someone used gender as a predictor (X1) of longevity (Y), would you expect women or men to live longer?
This calculator performs multiple linear regression with support for two or more predictor variables. It calculates regression coefficients, R-squared, adjusted R-squared, F-statistic for overall model significance, and individual t-tests for each predictor.

This particular example perfectly highlights why For Each Predictor Variable X is so captivating.
A core assumption of linear regression whether simple or multiple is linearity: the idea that there is a straight-line relationship between each predictor and the outcome variable.
In this chapter, we consider multiple regression and other models in which there are more than one predictor (or X) variable. This extends what we covered in the last chapter where we examined one predictor to multiple predictors.

extract p-value for specific predictor variable position model.pvalues[0]. The following examples show how to use each method in practice. Example: Extract P-Values from Linear Regression in Statsmodels.