4:5

4:5 is a ratio. Here are common ways to view it:

• As a fraction: 4:5 = 4/5 = 0.8
• As a decimal: 0.8
• As a percent: 80%
• Parts of a whole: total parts = 9, so first part is 4/9 ≈ 0.444, second part is 5/9 ≈ 0.556
• If you have a quantity x for the first part, the second is (5/4)x; or if you scale to a total T, first = 4/9 T and second = 5/9 T

If you want, tell me a specific context (e.g., a problem with a total, or a probability question) and I’ll work it out.