Create a central composite design for two factors using the rsm package.

(a) Create the uniform precision CCD and store the design along with ran-

dom numbers (simulated response) in a data frame.

(b) Use the Vdgraph package to make a variance dispersion graph or a frac-

tion of design space plot of the design you created.

(c) Repeat

(a) through

(b) for a face-centered cube design (i.e., CCD with axial points at ±1).

(d) Based on the graphs you made, which design do you prefer? State the reason.