A ratio can be written 3 ways, like the following:-
a to b
a:b
a
------
b
So, technically 9/36 is in ratio already but you can also write is as:-
9 to 36
or
9:36
Now we can simplify this:-
9 ÷ 9 1
--------------- = --------
36 ÷ 9 4
So, 9:36 reduced is 1:4 or 1 to 4, or 1 over 4 (1/4).
Hope i helped ya!!!!!!!!