I'm not sure if the last one is 14 1/2 or if it is 14 and then 1/2. So, here is 2 different ones.
-4, 1/2, 14, 21, 25
OR
-4, 14 1/2, 21. 25
Explanation:
Negative numbers are always less then postitive numbers, therefore -4 would go first. After you do the negatives, go to the positives and it is just least to greatest afterwards.