Based on what I have saved, I'd need to earn a pre-tax yearly income of 4.0%.

At 5.5%, I minus 1.5% for inflation, and there's my 4%.

Ahhhhhhh.
Reminds me of when one of our neighbors put their house up for sale. They priced it according to what they needed to buy the new house they wanted, and didn't even bother to ask what similar houses were selling for.

Needless to say, that's exactly backwards. You don't start with what you need. You start with what you can get. I think you've kinda started your questions from the middle instead of from the beginning.

Why do you "need to earn 4.0%"? How did you arrive at this figure?

What does "Based on what I have saved" have to do with anything?

Absent further details about your situation, I would make a completely blind guess that 4% comes from what you've heard about the 4% withdrawal rule. If so, then you've completely missed all the important details of how that figure came to be determined.