example:
data 1, 2, 2, 2, 10
Mean: 3.4 Median: 2 Mode: 2
Nice online tool to easily work these out https://www.calculator.net/mean-median-mode-range-calculator...
Of note I have no idea what the average family size is children wise, just going on longstanding data from UK that in itself may be out of date, though does highlight the point.
[EDIT fixed typo]
What matters in real life is generally not how often you are correct, but rather by how much you are wrong. What you need to minimise is not your error rate, but the consequences when you are wrong. You are free to make an infinite amount of mistakes, as long as you are sure to make them in such a way that they are comparatively insignificant.
Not sure were you went there, but the point is that you can overdetail in a way that abstracts from reality.