1. **State the problem:** A hot-air balloon rises 720 meters in 4 minutes. We need to find the rate at which it rises. 2. **Formula used:** Rate (speed) is calculated by dividing distance by time: $$\text{Rate} = \frac{\text{Distance}}{\text{Time}}$$ 3. **Apply the values:** $$\text{Rate} = \frac{720 \text{ meters}}{4 \text{ minutes}}$$ 4. **Simplify the fraction:** $$\text{Rate} = \frac{\cancel{720}}{\cancel{4}} = 180 \text{ meters per minute}$$ 5. **Interpretation:** The balloon rises at a rate of 180 meters per minute. **Final answer:** The hot-air balloon rises at a rate of **180 meters per minute**.