Astronomical observations show that the centre of mass of the Earth-Moon system is 4.7 times 10 to the power of 6 metres from the centre of the Earth….

Astronomical observations show that the centre of mass of the Earth-Moon system is 4.7 times 10 to the power of 6 metres from the centre of the Earth. The distance between the centres of the Earth and the Moon is 384.4 times 10 to the power of 6 metres. Find the mass of the Moon (Mm) in terms of the mass of the Earth (Me).