Problem 7 (10 points) You wish to explain y using the following multiple regression model and 32 obser- vations: y = Bo + Bx + B2x2 + B3x3 + . A linear regression package generates the following table of summary statistics: Intercept B B B3 Estimated Coefficient 44.200 -0.295 9.110 -8.700 Standard Error 5.960 0.118 6.860 1.200 Using the a = 0.1 significance level, which variables have coefficients significantly different from zero? [[Hint: Perform the t-test with Ho: B; = 0 against Ha: B; 0 for j = 0, 1, 2, 3. If Ho is rejected, you can say that the unknown coefficient 3; is significantly different from zero (based on the t-test).]]