Case statement from DQ

Hello folks,
My data source comes from an oracle DB which I'm using as a direct query.
The column I need to use is a decimal number type of data, which I cannot change in Power Query.
I need to create a new column with the range below, but I'm not sure how as I've tried creating a calculated column using SWITCH and a measure using IF. I'm also, not sure if I should change the data type within the measure from decimal to whole number.
If you could tell me how I can create a case statement to have a new column with the range below, it would be incredibly helpful. Many thanks! 

Below is a measure that I tried using the 'IF' statement, but it's wrong.