The topic for this questionnaire is "student life, academics, athletics", which is an important part of the question when determining if non-responses are important. In this case ChatGPT gets it correct, but explains the reason very poorly.
The more people you survey, the higher the confidence that the questionnaire is representative of the entire population, or the 'confidence interval'. Since the population was randomly sampled & non-responses don't correlate to the topic questions, you can assume that the 90 students are representative of the entire population with +- some confidence interval.
