[Lab report] Literature values in physics?

[IB-Adam]

Hello,

I've done an experiment where I investigated how the length of an conducting wire (in this case an iron wire) affects its resistivity. I know, according to theory, that the length is proportional to the resistance but how could I compare it with my own results?

The R-square value of my graph is 0.9996, almost 1, which suggests that it seems to be linear.

But again, to the question: How could I compare my results with theory? In chemistry it's just looking up a certain value in the Chemistry Data Book, but in physics you often investigate relationships. And how do you compare that?

Note: I can't compare the resistivity constant since I did not measure the temperature on the wire. However, my teacher said that there is a way to make a comparison between the experimental relationship with the theoretic relationship, but he doesn't want to say it! All I know is that it is not based on temperature

Any ideas?

/ Adam