1. **State the problem:** Calculate the volume of a cone-shaped megaphone with height $h=8$ inches and radius $r=9$ inches. 2. **Formula for volume of a cone:** $$V=\frac{1}{3}\pi r^2 h$$ where $r$ is radius and $h$ is height. 3. **Substitute values:** $$V=\frac{1}{3}\pi (9)^2 (8)$$ 4. **Calculate $9^2$:** $$9^2=81$$ 5. **Plug in:** $$V=\frac{1}{3}\pi \times 81 \times 8$$ 6. **Multiply 81 and 8:** $$81 \times 8=648$$ 7. **Simplify fraction:** $$V=\frac{1}{3}\pi \times 648=\pi \times \cancel{\frac{1}{3} \times 648}=\pi \times 216$$ 8. **Calculate volume:** $$V=216\pi \approx 678.58$$ 9. **Round to nearest tenth:** $$678.6 \text{ cubic inches}$$ **Final answer:** The volume is approximately $678.6$ cubic inches.