First, find the least common denominator. In this case, our least common denominator is 18 so we are going to rewrite our fractions with the lowest common denominator.
-Order From Least To Greatest Using Lowest Common Denominator-
4/18 < 11/18 < 12/18 < 15/18
We can now rewrite this using our original fractions and they are in order from least to greatest.