Answer
$$710\ V/\Omega$$
Work Step by Step
We have
$$
\frac{4800\ V }{ 6.72\ \Omega}=714.285\ V/\Omega
.$$
Now, round this product to two significant digits, which is the accuracy of the least accurate measurement. That is,
$$714.285\ V/\Omega=710\ V/\Omega$$
