The 1954 Statelessness Status Convention provided a definition of a stateless person (which has since become part of customary international law, according to the International Law Commission), and sets out a number of rights that stateless persons should enjoy.
The ratio of two integers P and Q can be expressed as P : Q or P/Q. In both cases, you may divided P and Q by their greatest common factor so as to express the ratio in its simplest form.
The mean is the average of the numbers. It is easy to calculate: add up all the numbers, then divide by how many numbers there are. In other words it is the sum divided by the count. 6, 11, 7. 1  Add the numbers: 6 + 11 + 7 = 24.  Divide by how many numbers (there are 3 numbers): 24 / 3 = 8.