Align a list of numbers
05AB1E, 19 18 15 10 bytes
Code:
'.©«®δkZαú

Try it online! Explanation:
'.©«             # append . to each element
    ®δk          # Find index of . for all elements
       Z         # Get the largest
        α        # Get the absolute difference between the indices
         ú       # Pad by that much