Multiple Regression Q & A

2.4. Multiple Regression Q & A#

  1. The term multiple regression simply means having multiple x variables. (Whereas “simple regression” like last week’s examples have just a single \(x\) variable). Note that the \(x\) variable may be called a “control variable” or an “explanatory variable”. What is the difference between a control variable and an explanatory variable?

  1. How many \(x\) variables can you include in a regression analysis?

  1. Last week, we saw the regression equation \(y=a+bx\) What is the form of the regression equation when there are several \(x\) variables?

The regression equation is additive. We can add more slope*\(x\) elements to the equation. Note that there is always only one intercept! Also note that in multiple regression we estimate a slope (\(b\)) for each \(x\) variable.

  1. How does the interpretation of the intercept change in multiple regression?