Consider the model: E1y2 = b0 + b1x1 + b2x2 + b3x2 2 + b4x3 + b5x1x2 2 where x2 is a quantitative model and where x1 = e 1 received treatment 0 did not received treatment The resulting least squares prediction equation is y = 2 + x1 - 5x2 + 3x2 2 - 4x3 + x1x2 2

a. Substitute the values for the dummy variables to determine the curves relating to the mean value E1y2 in general form.

b. On the same graph, plot the curves obtained in part a for the independent variable between 0 and 3. Use the least squares prediction equation.