title:
  Data from table 3.1, page 39.
  Input 3.4 page 41.
  Output page bottom 41, top 42, output 3.8.
data:  
  file is ch3.dat;
  format is free;
  type is correlation means stdeviations;
  nobservations = 343;
variable:  
  names are y1 y2 y3 age prob; 
  usevar =  y1 y2 y3 age;
analysis:  
  type = general meanstructure;          
model: 
  int    by y1@ 0.577 y2@0.577  y3@0.577;**
  lin    by y1@-0.707 y2@0      y3@0.707;
  quad   by y1@ 0.408 y2@-0.816 y3@0.408;
  [int lin quad];
  [y1-y3@0];
  y1-y3@0;
  int lin quad on age;