10. Create a blocked response surface design for four factors.

(a) Use SAS ADX to create an orthogonally blocked central composite de-

sign. How many runs are in this design, and how many runs are in each block?

(b) Use SAS ADX to create an orthogonally blocked Box-Behnken design.

How many runs are in this design, and how many runs are in each block?

(c) Supposing that only 6 runs can be made in each block, take the central composite design you created in

(a) and use proc optex to block it into ve blocks of six runs each.

(d) Take the Box-Behnken design you created in (b), and add three center points, and then use proc optex to block the runs into ve blocks of six runs each.

(e) Import the designs you created in

(c) and

(d) into SAS ADX, create the variance dispersion graphs, and compare them to the variance dispersion graphs of the orthogonally blocked designs you created in

(a) and (b).

Do you lose much by reducing the block size?