When evaluating a multiple regression model, for example when we regress dependent variable Y on two independent variables X1 and X2, a commonly used goodness of fit measure is:

Adjusted-R2

Step-by-step explanation:

When evaluating a multiple regression model, a commonly used goodness of fit is the adjusted-R2. It allows for a comparison of regression models with multiple predictors or independent variables. The addition of independent variables usually causes the model to be more reliable. The adjusted-R2 considers the effect of additional independent variables. It usually adjusts for the number of terms in the model.

answer: 12   they all have at least 28 days

step-by-step explanation: haha