Question

Why a regression coefficient could change in value and sign, even become statistically no significant, when another variable is entered into the model? Explain and justify your answer. (10 points)

Answer 1

Regression coefficient explain the relatinship between a predictor variouble and the response. So , they are the estimates of unknown population parameters. A coefficient value speak to the mean change in the response given a one unit change in the predictor. Regression coefficient could change in value and sign because the sign of each coefficient shows the connection between a predictor variable and response variable.

A Positive sign demonstrate that as the predictor variable increses, the response variable also additionally increases.

A Negative sign ishows that as the predictor variabe increases, the response variable decresese.