Answer
$$4.8 \mathrm{\ MeV}
$$
Work Step by Step
The energy transferred is
$$
\begin{aligned} Q &=\left(m_{U238}+m_{n}-m_{U239}\right) c^{2} \\ &=(238.050782 \mathrm{\ u}+1.008664 \mathrm{\ u}-239.054287 \mathrm{\ u})(931.5 \mathrm{\ MeV} / \mathrm{u}) \\ &=4.8 \mathrm{\ MeV} \end{aligned}
$$
