* copper.sas, acid copper pattern plating experiment, 
* Table 16.16 (page 579);
* First-order response surface regression;
options ls=72;
;
* Enter data of the first order design and code levels;
DATA COPPER;
  INPUT XA XB S;
  ZA = (XA - 10.5);
  ZB = (XB - 36)/5;
  LINES;
   9.5  31  5.60  
   9.5  41  6.45       
  11.5  31  4.84         
  11.5  41  5.19         
  10.5  36  4.32         
  10.5  36  4.25         
;
* Analysis of the first order design;
PROC GLM;
  MODEL S = ZA ZB;
;
* Add model terms to test for lack-of-fit;
PROC GLM;
  MODEL S = ZA ZB ZA*ZB ZA*ZA;