List three variables (X1, X2, X3) you'd include in a Multiple Regression Model in order to better predict an outcome (Y) variable. For example, you might list three variables that could be related to how long a person will live (Y). Or you might list three variables that contribute to a successful restaurant. Your Regression Model should have three variables that will act as "predictors" (X1, X2, X3) of a "criterion" (Y').