Answer
$I = 1.91\times 10^3~W/m^2$
Work Step by Step
We can find the intensity:
$I = \frac{E^2}{2c~\mu_0}$
$I = \frac{(B~c)^2}{2c~\mu_0}$
$I = \frac{B^2~c}{2~\mu_0}$
$I = \frac{(4.00\times 10^{-6}~T)^2~(3.0\times 10^8~m/s)}{(2)~(4\pi\times 10^{-7}~H/m)}$
$I = 1.91\times 10^3~W/m^2$
