Answer
See explanation.
Work Step by Step
a. $$E_{max}=\sqrt{\frac{2I}{\epsilon_0 c}}$$
$$E_{max}=\sqrt{\frac{2(1.4\times10^3W/m^2)}{(8.854\times10^{-12}F/m)(3.00\times10^8m/s)}}$$
$$= 1.03\times10^3N/C$$
$$ B_{max}=\frac{E_{max}}{c}=3.42\times10^{-6}T $$
b. At a distance r from the sun, the total average power from the sun is spread over a spherical surface, of area $4 \pi r^2$.
$$P_{av}=I4\pi r^2=(1.4\times10^3W/m^2)(4 \pi)(1.50\times10^{11}m)^2=4.0\times10^{26}W $$