Can you help please?!

 

I play a fantasy football game, where two variables (age & computer rating – there is a constant of ‘position’) lead a total value of that player. The older you get, the cheaper you the player becomes and the higher the computer rating the player has the more expensive he becomes. Here are some examples:

 

 

Rating (x) Age (y) Value (z)

69 24 2093

66 23 1540

66 25 1298

66 27 1154

66 31 871

64 30 704

65 25 1125

61 36 0

38 23 12

40 30 0

39 17 44

44 17 109

60 17 1103

 

There must be some formula involving x and y which equals z, but I can’t for the life of me work it out!?

 

Any help would be greatly appreciated.

Well, there's no guarantee that you have enough information to find the actual function, but you could try approximating it by first graphing x and y vs. z and then using an appropriate polynomial (or other) approximation. If you don't know about "least squares" approximation, you might want to read up on that. I do, but it's honestly been a while so I would have to double-check myself before I risk explaining anything wrong and leading to even more confusion.