The following is the quadratic regression equation for a sample of n = 25:

a. Predict Y for X1 = 2.
b. Suppose that the computed tSTAT test statistic for the quadratic regression coefficient is 2.35. At the 0.05 level of significance, is there evidence that the quadratic model is better than the linear model?
c. Suppose that the computed tSTAT test statistic for the quadratic regression coefficient is 1.17. At the 0.05 level of significance, is there evidence that the quadratic model is better than the linear model?
d. Suppose the regression coefficient for the linear effect is -3.0. Predict FforX, = 2.