前面NJ 和PA的两个数据我都做出来了，但是最后那个ttest 怎么求啊？T的一个上标a的标注是：Test of equality of means in New Jersey and Pennsylvania. 谢谢各位大牛~

下面的是求NJ和PA的代码：
Proc means data=final (WHERE = (NJ = 1));
var bk kfc roys wendys CO_OWNED FTE PercentageFull WAGE_ST MW FULLMEAL HRSOPEN BONUS;
run;
Proc means data=final (WHERE = (PA = 1));
var bk kfc roys wendys CO_OWNED FTE PercentageFull WAGE_ST MW FULLMEAL HRSOPEN BONUS;
run;