OK - depending on what "fixed" means, it's probably a safe ratio.... you could be a little more aggressive if you wanted, but not by much.
I am not a financial advisor, but my general plan is to make sure as I near retirement to have more and more of my portfolio in "safe" investments (cash and bond, etc). I don' think I'll have more than say 7 years worth of living expenses in safe investments though... I just need enough to weather 5-7 years of a bad market should it come to that.