Cube and sphere!

Let us say the radius of the sphere is $r$ and the side of the cube is $l$ . According to the question: $\dfrac 43 \pi r^3=l^3\\l=\sqrt[3]{\dfrac 43 \pi r^3}$

Now the ratio of the surface areas of the sphere to cube will be: $\dfrac{4\pi r^2}{6l^2}=\dfrac{4\pi r^2}{6\times \left(\dfrac 43 \pi r^3\right)^{\frac 23}}\\=\dfrac{4\times \pi^\frac 13}{6\times \left(\dfrac 43\right)^\frac 23}\approx\boxed{0.8.059}$