How did this person get this number for calculating planetary energy budget formula?

Question

Here is the problem, I keep getting it like this: $\sqrt[4]{\frac{1370\left(1-0.3\right)-4.367}{\left(5.67\cdot 10^{-8}\right)}} = 360.21$

How does this person get the value 256.155K?

What am I missing/doing wrong?

Thank you

Answer 1

\begin{align}\sqrt[4]{\frac{1370\left(1-0.3\right)-4.367}{\left(5.67\cdot 10^{-8}\right)}} &= 360.21 \\ \sqrt[4]{\frac{1370\left(1-0.3\right)+4.367}{\left(5.67\cdot 10^{-8}\right)}} &= 361.04 \qquad (2\, \text{dp}) \end{align}

Not really sure sure what's going on....