equation of a graph

[Tim Chase]

> but i want to find *"best-fit curve" *

What type of curve?  Polynomial (of which your rejected linear is 
a low-order variant)?  Exponential or logarithmic?  Bell curve? 
S-curve?  Circle?  Axis-aligned ellipse? non-axis-aligned 
ellipse?  There are lots of curvy possibilities here...

-tkc
(Blast...if this post showed up a couple days later, I could 
abuse Talk Like A Pirate day to say things like "avast, ye 
s-curvy sea-dog" or intone a pirate's parrot with "Piecewise of 
eight, Piecewise of eight" and "Polynomial want a cracker")