1. **Problem Statement:** Evaluate the expression $\frac{0.631\ \text{Mm}}{(8.60\ \text{kg})^2}$ and express the answer in $\text{km/kg}^2$ to three significant figures. 2. **Formula and Unit Conversion:** - 1 Mm = 1000 km - The expression is $\frac{0.631\ \text{Mm}}{(8.60\ \text{kg})^2} = \frac{0.631 \times 1000\ \text{km}}{(8.60)^2\ \text{kg}^2}$ 3. **Calculation:** $$ \frac{0.631 \times 1000}{8.60^2} = \frac{631}{73.96} $$ 4. **Simplify:** $$ \frac{\cancel{631}}{\cancel{73.96}} \approx 8.53 $$ 5. **Final Answer:** $$ 8.53\ \text{km/kg}^2 $$