Using the approximations given in Problem 55, find

(a) The altitude above Earth's surface where the magnitude of its magnetic field is 50.0% of the surface value at the same latitude;

(b) The maximum magnitude of the magnetic field at the core-mantle boundary, 2900 km below Earth's surface; and the

(c) Magnitude and

(d) Inclination of Earth's magnetic field at the north geographic pole.

(e) Suggest why the values you calculated for (c) and (d) differ from measured values.