Given the fitted response function

̂y = 72.0 + 3.6x1 − 2.5x2 which is found to fit well in a localized region of (x1, x2).

(a) Plot contours of constant response, y, in the (x1, x2)

plane.

(b) Calculate and plot the path of steepest ascent generated from this response function. Use x1 to determine the path, with Δx1 = 1.