*there, if without specifying anything in output statement, dataset2 would only include the default statistics, which is nothing to do with your

specification in means statement;note that, the name of statistics is arbitrary, for example, you can say, n=sample p25=q1, and so on;

*thanks;

i find that all my replies are not exactly shown the same as I hoped. please take your own judgement for that.

basically,

proc means data=dataset; *you don't need to write those statistics here;
  var _numeric_;
  output out=datasets
            n=sample nmiss=Nmissing min=minimum max=max p5=p5 p10=p10 p25=q1 p75=q3 p50=median p90=p90 mean=average std=std;
            *you have to list all what you want here otherwise you will get the default statistics about which you were complaining;
            *arbitrary names,but you have to correctly spell the statistic names;
run;

thanks,