Physics question below?

Question

In an EM wave traveling west, the B field oscillates vertically and has a frequency of 80.0 kHz and an rms strength of 6.75 X 10^-9 T. What are the frequency and rms strength of the electric field, and what is its direction?

Answer 1

I don't remember how to calculate the strength of the electric field but it must be perpendicular to the magnetic field so it must be horizontal and perpendicular to the direction of motion of the wave so it must be oscillating north-south.