The CI is for the mean, not for the entire data. This is the difference between a confidence and a prediction interval: https://stats.stackexchange.com/question

The CI is for the mean, not for the entire data. This is the difference between a confidence and a prediction interval: https://stats.stackexchange.com/questions/225652/prediction-interval-vs-confidence-interval-in-linear-regression-analysis https://stats.stackexchange.com/questions/225652/prediction-... I do agree that it's fairly noisy though.