Answer:
2, 1, 3, 4
Explanation:
For future reference:
Make all the numbers (accept for the second one) into a common form. For example a decimal.
For the first one, it will simplify into 3/2 since both 9 and 4 can be easily rationalized.
The second can't be written as a decimal, but it will easily become the least greatest number.
The third is already a decimal and the fourth could just be divided 5/3 using a calculator.
From there you'll have
1.5, /5, 2.5, and 1.67