A simple random sample of size n is defined to be a sample of size n chosen in such a way that every unit in the population has the same chance of being selected. a sample of size , n, chosen in such a way that every unit in the population has the same chance of being selected. a sample of size n chosen in such a way that every unit in the population has a known nonzero chance of being selected. a sample of size , n, chosen in such a way that every unit in the population has a known nonzero chance of being selected. a sample of size n chosen in such a way that every set of n units in the population has an equal chance to be the sample actually selected. a sample of size , n, chosen in such a way that every set of , n, units in the population has an equal chance to be the sample actually selected. a sample of size n chosen in such a way that each selection is made independent of every other selection. a sample of size , n, chosen in such a way that each selection is made independent of every other selection. all of the above. They are essentially identical definitions. all of the above. They are essentially identical definitions.