SAS Consulting, Department of Statistics 

Adding the population mean to every observation in the original data set.

data a;
input x @@;
cards;
5 3 4 2 4
;

proc means noprint data=a;
output out=m1(keep=xmean) mean=xmean;

data b;
if _n_=1 then set m1;
set a;

proc print;
run;