Consider the multiple regression model shown next between the dependent variable Y and four independent variables X1, X2, X3, and X4, which result in the following function: Y = 33 + 8X1 - 6X2 + 16X3 + 18X4 For this model, there were 49 observations; SSR = 1,512 and SSE = 600. The critical F-value at the 1% level of significance is