You're doing exact comparisons on floating point numbers. Don't ever do that. Multiply everything by 100 so you have integers everywhere, and try again.

And your code doesn't even compile, it's full of syntax errors. My thoughts are that you haven't even tried this in Perl, but instead transalted it here from some other programming language, just for the purpose of posting it here.

Update: My mistake, there wheren't as many errors as I first thought. I tried multiplying all numbers by 100, and it gives a different result now, more like you expected.

You've clearly been hit by the "floating point numbers are not exact" syndrome.