Answer: 3.33.

## Explanation The Variance Inflation Factor (VIF) is calculated as: $$VIF_j = \frac{1}{1 - R_j^2}$$ Given: - $R_j^2 = 0.7$ Calculation: $$VIF_j = \frac{1}{1 - 0.7} = \frac{1}{0.3} = 3.33$$ Therefore, the VIF for $X_j$ is 3.33, which corresponds to option C. **Interpretation**: A VIF of 3.33 indicates moderate multicollinearity, as VIF values above 5-10 are typically considered problematic.

Author: LeetQuiz Editorial Team