* SAS code to fit toxicity data from Table 11.1;
 options linesize = 70;

 data actox;
   input stime ievent @@;
   censflag=1-ievent;
   cards;
 1 1  2 0  3 1  4 1  4 1  4 0  5 0  6 1  8 1  9 0

 proc lifereg;
   model stime*censflag(1)=/distribution=Weibull;

 run;