Calculating average by two varaiables

[vishyy]

Hi 

I have three columns supoose named as int_rate, grade and sub_grade.

Sample value are as below 

int_rate grade sub_grade

0.1701      B      B4 

0.0788      C      C5 

I need to calculate average int_rate by grade and sub_grade.

Thanks & regards 

Vishal 

[Jagadishkatam]

proc means data=have nway;
class grade sub_grade;
var int_rate;
output out=want mean=;
run;