`How do you write 5 is to 1 as 20 is to 4 as a proportion in a fractional notation?
To write "5 is to 1 as 20 is to 4" as a proportion in fractional notation, you would write it as:
5/1 = 20/4
This simplifies to:
5/1 = 5/1
Therefore, the proportion in fractional notation is 5/1 = 20/4.