The following data were collected by a mechanical engineer studying the performance pf an industrial process for the manufacture of cement blocks, where X1 is travel x2 is -vibration, and y is a measure of operating efficiency. All values are in coded units. High values of y .are desired.
Do the following:
(a) Fit a first-order model to these data using the method of least squares.
(b) Draw contour lines of the fitted response surface.
(c) Draw the direction of steepest ascent on this surface.
(d) Criticize your analysis.