Sampling and a misleading conclusion

A fictional school wants to learn whether its students play organized sports regularly. It surveys only members of the basketball team and finds that most answer yes. A learner declares that most students in the whole school must therefore play organized sports. Another suggests surveying more basketball players without changing the selection rule. A third identifies the target population and the over-represented group. The task asks what the sample can support and how selection could be improved. No actual school, percentage or guaranteed random procedure is supplied. The example is a mathematical model for interpreting evidence, not an official research claim. A good explanation should distinguish the number of answers from the way participants were chosen and avoid pretending that a larger biased sample automatically becomes representative.