In general for fitted regression model what does adjusted R

In general for fitted regression model what does adjusted R squared do that \"regular\" Squared does not It always gets large as more x variables are to the model, whether the variables are useful or not. It forces R-Squared to be between -1 and 1 It tells us the increase on the mean of Y for a one-unit increase in x holding all other variables fixed. It allows us to conduct the model F test

Solution

option (3) is correct, it actually reduces infalted R-square on adding useless extra variables