What diameter wire should be used for particular resistance?

[Kastner86]

Homework Statement

If 49 m of nichrome wire is to have a resistance of 16.0 ohms at 20 degrees celsius, what diameter wire should be used?

Homework Equations

R = $$\rho$$ x L / A

A = $$\Pi$$ d^2 / 4

The Attempt at a Solution

well i know what I'm looking for, that is d (diameter)

and d = $$\sqrt{}$$(4$$\rho$$L/$$\Pi$$R)

I don't know what the value of $$\rho$$ is.

I know it is supposed to be the resistivity of the material, at a certain temperature, but I have no idea how to include it in the equation.

Please Help!

 

[Delphi51]

You can get an estimate of the resistivity at room temperature here:
http://en.wikipedia.org/wiki/Nichrome