* 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 lifetest;
   time stime*censflag(1);

 proc lifereg;
   model stime*censflag(1)=/distribution=Weibull;
   output out=wout quantiles=.1 .5 .9 std=std p=predtime;

 data wout1; set wout;
   ltime=log(predtime);
   stde=std/predtime;
   uclw= exp(ltime+1.96*stde);    * upper limit on LT(Q);
   lclw= exp(ltime-1.96*stde);    * lower limit on LT(Q);
 proc print;

 run;