2.4. (10%) A regression analysis involving 45 observations relating a dependent variable and two independent variables resulted in the following information.

$$\hat{Y} = .408 + 1.34x1 + 2x2$$

The SSE for the above model is 49.

When two other independent variables were added to the model, the following information was provided.

$$\hat{Y} = 1.2 + 3x1 + 12x2 + 4x3 + 8x4$$

This model's SSE is 40.

We want to test whether or not the addition of 2 variables to a model will be statistically significant.