This process of converting a continuous variable to a discrete variable is known as "discretizing," and there is a big literature about how to do it (and why you might not want to!).  For an introduction, see David Pasta's paper: http://support.sas.com/resources/papers/proceedings09/248-2009.pdf ... View more

That's because variable AGE_RANK is created by Proc Rank. So you need to use the output data set in Proc Freq (so "want" instead of "xxx.xxx"). If you've got Proc Surveyselect licensed then you could also use Proc Rank to create a strata variable which you then use as part of Proc Surveyselect. There is also a data step approach under this link: http://support.sas.com/resources/papers/proceedings09/058-2009.pdf ... View more

Thanks! I copied and pasted all your recommendation in my special electronic folder! You're so awesome! ... View more