<P> 2 . In the case that any selected person is returned to the selection pool (i.e., can be picked more than once): </P> <Dl> <Dd> P = 1 − (1 − 1 N) n = 1 − (999 1000) 100 = 0.0952 ⋯ ≈ 9.5% (\ displaystyle P = 1 - \ left (1 - (\ frac (1) (N)) \ right) ^ (n) = 1 - \ left ((\ frac (999) (1000)) \ right) ^ (100) = 0.0952 \ dots \ approx 9.5 \%) </Dd> </Dl> <Dd> P = 1 − (1 − 1 N) n = 1 − (999 1000) 100 = 0.0952 ⋯ ≈ 9.5% (\ displaystyle P = 1 - \ left (1 - (\ frac (1) (N)) \ right) ^ (n) = 1 - \ left ((\ frac (999) (1000)) \ right) ^ (100) = 0.0952 \ dots \ approx 9.5 \%) </Dd> <P> This means that every student in the school has in any case approximately a 1 in 10 chance of being selected using this method . Further, all combinations of 100 students have the same probability of selection . </P>

What are the distinguishing features of simple random sampling