Physics homework help please! Please show steps!?

Question

Near the Earth's poles the magnetic field is about 1.08 G. (1 G = 1 10-4 T.) Imagine a simple model in which the Earth's field is produced by a single current loop around the equator. What current would this loop carry?

I was trying to use this:

Answer 1

Use Biot-Savart Law. You'll want to find the B-field at the pole measuring the this loop.

r=equitorial radius=6378 km and R=polar radius=6357 km

The loop of current at the produces a field as measured through the poles equal to uIr^2/(2(r^2+R^2)^(3/2))=1E-4 T

4πE-7I(6378^2)/(2(6378^2+6357^2)^(3/2)=1E-4

solving for I we get 2.9E6 A