So, we know that the formula for the magnetic field produced by a wire is given by $\frac{\mu I}{2 \pi r}$. I calculated the magnetic field at the center of the wire as as $B = B_{straight wire} + B_{loop} = \frac{\mu I}{2 \pi r} * 2 \pi r + \frac{\mu I}{2 \pi r}$, but this was wrong.