The following picture appeared on my Facebook feed some time ago, and is a perfect example of how when it comes to statistics, many go astray.
I originally saw this post on the Facebook page “The LAD Bible”, posted on June of 2014, and now it has almost 350K likes.
Reading the comment section is amusing for someone who understands this mathematical average is complete nonsense. A common theme of the comments are “Math bitch!”, “Science rules!”. Not that I expect much intelligence in the comment section of FB, but still, pretty disheartening.
One of the top comments is “This should be the type of shit they put on exam papers, not bullshit algebra.” It seems to me that our dear commenter is incapable of understanding “this type of shit”, thus calls Algebra “bullshit” and sadly at the end fails in both statistics and mathematics exams. Another commenter suggests “Math.. the silent killer of swag 🙂 ” Indeed, I suspect he means his own “swag”, if he had any.
Simply put, the conclusion is absolute nonsense. “You guys had 3.5 pints each day” is completely false. Instead, “You guys had 3.5 pints on average* each day” is correct. Then we clearly see what went wrong: The average of a set of data does not say anything about its distribution, and therefore is irrelevant here. Without knowing the distribution of drinks in each day between each person calculating its mean is misleading and nonsensical. The group of boys could have drunk on the first day and the last day, and not anything in between. Also, some might have had more drinks than others. In which case the sarcasm of the last sentence simply dies: It very well could have been wild.
* Average = Mean