I have a small question, when I want to show mathematically that independent variable Y is negatively related to X, how do I show this? Is there is certain sign I can use? The sentence is: Y decreases if X is increased. Anybody good at statistics?? Cheers for any help!

I guess mathematically, the first one is actually correct. But I was hoping more for a statistical way of writing down a correlation. Thanks anyway!

The correct equation is [ y = - x ]. You can easily imagine it graphically, for every increasing value of x, y decreases, and a simple straightline graph is formed. If you keep the slope to 1 then you get [ y= - x] but still you can switch between slopes and starting point , in this equation the line passes through origin because there isn't horizontal shift present in the equation. [edit], here is the graph

There is a greek sign for proportional to, its kind of like a lower cased alpha except with a tail on the top on the right. In other words, an infinite sign with the circle on the right half cut off. So to write it you would just write y (proportional sign thingy) -x

I saw it here, but couldn't copy/paste the symbol... (infinity laying on it's side, about half way down the page) proportional sign http://whatis.techtarget.com/definition/0,,sid9_gci803019,00.html amazing what google has 2 offer...ehemm.. lolz