1. State the problem: Convert 51 miles per hour (miles/h) to kilometers per hour (km/h) using the conversion factor $1 \text{ km} \approx 0.6214 \text{ miles}$. 2. Set up the conversion equation: To find kilometers per hour, divide the speed in miles per hour by the miles per kilometer conversion factor. 3. Calculate the speed in km/h: $$\text{Speed in km/h} = \frac{51}{0.6214}$$ 4. Perform the division: $$\frac{51}{0.6214} \approx 82.0703$$ 5. Round the result to the nearest tenth: $$82.1$$ **Answer:** The speed is approximately 82.1 km/h.