I was aiming at statistics fallacies, but sure, it’s a basic requirement to understand math.
One curious example that happened to me: I was modeling some CoC model for personal reasons and decided to simulate pushing rolls, the simulation proved that pushing a roll raises the chance of success in ~20%.
Half of the people have below-median knowledge of statistics.
The amount of people with below-average knowledge of statistics is likely higher than that if we assume that few people have a lot of knowledge of statistics and most people very little.