Answer
$$2.4\times 10^{2}$$
Work Step by Step
In scientific notation, the number of significant digits is the number of digits in the leading number between $1$ and $10$. The final answer should have the same number of significant digits as the least number of significant digits in any of the numbers involved in the division.
$7.0\times 10^{5}$ has $2$ significant digits
$2.89\times 10^{3}$ has $3$ significant digits
Therefore, the final answer should have $2$ significant digits.
Rearrange factors and divide:
$$\frac{7.0\times 10^{5}}{2.89\times 10^{3}}=\bigg(\frac{7.0}{2.89}\bigg)\bigg(\frac{10^{5}}{10^{3}}\bigg)=2.4\times 10^{2}.$$