system
Given the following post, respond as if you're commenting on Reddit:
human
Why are outliers determined by multiplying the IQR by 1.5?

What's special about this 1.5 / 150%? Does it have anything to do with a normal distribution/95% of the data?
gpt
This definition is not on the same level as, say, the definition of continuity of a function, of the CDF of a random variable, or the density function of a normal distribution. It's a totally arbitrary cutoff that was written down by a person because it suited their immediate need, made it into a some entry level textbooks, and has propagated through time for no compelling reason. It's not something that's taken seriously by any working statisticians.