Sunlight at Mars has a power of 586 W for each square metre, and Mars reflects 25 % of it…

Sunlight at Mars has a power of $586$ W for each square metre, and Mars reflects $25\ \%$ of it. Take Mars to have no greenhouse effect, so the heat it radiates balances the sunlight it takes in over its whole surface: $S(1 - A)/4 = \sigma T^4$. Use $\sigma = 5.67 \times 10^{-8}\ \text{W/(m}^2\ \text{K}^4\text{)}$ and $b = 2.898 \times 10^{-3}$ m K. Find:

1. the power each square metre of the surface takes in on average,
2. the average temperature of the surface,
3. the wavelength at which the surface shines most strongly,
4. the factor by which sunlight at Mars is weaker than at the Earth, where it is $1361$ W/m².