Answer
$(5\sqrt3, -4)$
Work Step by Step
RECALL:
The midpoint of $(x_1, y_1)$ and $(x_2, y_2)$ can be found using the midpoint formula
$\text{midpoint}=\left(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\right)$
Use the formula above to obtain:
$\text{midpoint}
\\=\left(\dfrac{7\sqrt3+3\sqrt3}{2}, \dfrac{-6+(-2)}{2}\right)
\\=\left(\dfrac{10\sqrt3}{2}, \dfrac{-8}{2}\right)
\\=(5\sqrt3, -4)$