Answer
$743\times10^6 \ m$
Work Step by Step
The distance between the two is an average of $779 \times 10^9 m$. The sun weighs $1.989\times 10^{30} \ kg $, and Jupiter weighs $1.898 \times 10^{27}\ kg $. Thus, we use the equation for center of mass to find:
$\frac{(1.898 \times 10^{27}\ kg)(779 \times 10^9 m)}{(1.989\times 10^{30})+(1.898 \times 10^{27}\ kg)}=743\times10^6 \ m$