1. **State the problem:** We need to estimate the mass of an iron block with dimensions 3.1 cm, 4.9 cm, and 2.2 cm and density 7.87 g/cm³, then check if Sam's estimate of 2.4 kg is reasonable. 2. **Calculate the volume:** Volume $V = \text{length} \times \text{width} \times \text{height} = 3.1 \times 4.9 \times 2.2$ cm³. 3. Simplify the volume calculation by rounding the dimensions for easier estimation: $3.1 \approx 3$, $4.9 \approx 5$, and $2.2 \approx 2$. So approximate volume $V \approx 3 \times 5 \times 2 = 30$ cm³. 4. **Calculate the mass:** Mass $m = \text{density} \times \text{volume} \approx 7.87 \times 30 = 236.1$ g. 5. Convert grams to kilograms: $236.1 \text{ g} = \frac{236.1}{1000} = 0.2361$ kg. 6. Compare with Sam's estimate: Sam says about 2.4 kg, our rough estimate is about 0.24 kg. **Conclusion:** Sam’s answer is not reasonable because the estimated mass based on volume and density is about 0.24 kg, which is much smaller than 2.4 kg.