Three electronic devices have the following power ratings:
• Portable music player: 120 mW
• Smartphone charger: 6 W
• Laptop power adapter: 65 W
(i) Convert each of the above ratings into a common unit of watt or its decimal multiples so that a direct numerical comparison is possible.
(ii) Arrange the devices in ascending order of power consumption.
(iii) Express the power of the laptop adapter in horsepower to three significant figures.