Hello all, Im trying to do this magnetic field lab and am having trouble with the very last question. It goes: "Assuming the equation (Ampere's Law: B=unI) applies for the solenoid, calculate the value and uncertainty of u (permeability of free space) using the graph of B vs. n. In this part of the experiment we had a constant current through a slinky and measured the magnetic field as we changed the number of turns of the slinky. I made my graph os B vs. n and it has a exponential looking relationship so i chose that as my trendline in Excel. Is this correct of should it have been a Power trendline? I chose exponential since it fits the data better. The equation of my exponential trendline was y=18.473e^(15.161x) so n is y and x is b and the rest of the garbage there is u and I. If i could only isolate the u and I....what i tried was multiplying both side by ln but i got stuck becasue i dont remember my log rules :-(. What i have right now is ln(n)=15.161x*2.91631. Am i on the right track? i also have the table of values and graph of this if it would help any.