libname sasdata '\\storage.wpi.edu\academics\courses\MA\SAS-Data\sasdata8';
proc sort data=sasdata.lightbulbs_d18 out=lightbulbs_d18;
by name;
run;
proc summary data=lightbulbs_d18;
var lifetime;
by name;
output out=lightbulb_means mean=ybar;
run;