I wrote in a document something similar to this:
Based on the collected samples, we hope to infer ...
I was asked to provide a citation for my claim. I guess I can claim that I don't need a citation because sample based inference is well-known, but it made me question myself.
Why can we say that we can characterize a populations based on some samples? Who came up with this and where is their research?
I was thinking of the central limit theorem, but my understanding is that it only applies to populations that have distributions that can be approximated with a normal distribution. So the question is whether the claim is even true that we can use samples to make statistical inferences even when the population distribution is unknown. If yes, what is the theorem that says this.