title " "; 
data xtrans; keep Y X sqrtx; 
 do obs = 1 to 100; 
  X = 100*ranuni(123); 
  sqrtx=round(sqrt(x),.1); 
  Y = 2 + 3*sqrt(x) + 2*normal(123); 
  Y = round(Y,.1); 
 output; end; 

 ***************************
 Throw in outlier 
 ***************************;
  Y = 20; X=169; sqrtx=13; 
  output; 
****************************/;
proc sort; by x; 

proc reg; model Y = sqrtx; output out=out1 p=ps r=rs; 
proc reg; model Y = x; 
output out=out2 predicted=px r=rx; 
proc means css; var rs rx; where Y<19; run; 

*** Graphics ***; 
goptions reset=all; 
proc gplot data=out2; 
plot Y*x/legend;
proc gplot data=out2;  where X<99;
plot (Y ps px)*x/overlay; 
symbol1 v=dot i=none c=black; 
symbol2 v=circle i=join c=red; 
symbol3 v=circle i=join c = green; 
run; 
proc gplot data=out2;  where X < 99; 
plot (rs rx)*x/overlay vref=0; 
symbol1 v=dot i=needle c=red; 
symbol2 v=circle i=needle c=green h=1.2;
run;