Answer these statistic questions:

1. In a bivariate linear regression, we test the slope of the regression line to see if it is significantly different from zero (0). If it isn’t, what is our best estimator of the Y variable?

2. In coding binary (dummy) variables, why do we only code the number of categories minus one?

3. If you take the R² values from a series of bivariate (one dependent variable) regressions and add them up, will they total the R² value from a multiple regression for the total set of the same variables? Explain.

**Subject Mathematics Applied Statistics**