909
Study of 8k Posts Suggests 40+% of Facebook Posts are AI-Generated
(originality.ai)
This is a most excellent place for technology news and articles.
The proportion of the total population size is almost irrelevant when you use random sampling. It doesn't rely on examining a large portion of the population, but rather that it becomes increasingly unlikely for the sample set to deviate dramatically from the population size as the number of samples rises. This is a function of the number of samples you take, decoupled from the population size.
https://en.wikipedia.org/wiki/Sampling_(statistics)
Usually if you see a major poll in a population, it'll be something like 1k to 2k people who get polled, regardless of the population size.