If you have 9:8 and you want to make it a unit ratio, would it be 1.125:1 or just 1.125?
Consider this example.
You have ten pencils with you. Your friend has 20 pencils. In normal practice you would say my friend has two times as many pencils as mine. You didi't tell that the pencil ratio between you and friend is 10:20 or 1:2. If in an ratio one part is 1 so we can say the other part along as the ratio. In this example you would not say 1:2 but twice than mine. The term twice automatically reflects that the other part is 1.
So in your question you can say ratio 9:8 as in terms of whole numbers. When you make one side to 1 you can say the other side number as the ratio. what ever you say even 1.125:1 or 1.125 both reflects the same ratio.