“arithmetic mean” is well defined (“the average as we know it” is not a particular sensible phrase to use in a subthread where the point in debate is specifically whether the average refers to one specific thing.)
That doesn’t make the word salad sentence used later in the article— “the mean is the arithmetic average”(emphasis added)—make any sense. Were it “the average is the arithmetic mean” it would merely be wrong, but at least make sense (and it would be making the same incorrect point it was being cited to support), but flipping “mean” and “average” so it claims that the former is the “arithmetic” version of the latter goes beyond wrong into being a pile of words that are individually sensible but don’t mean anything, right or wrong, as assembled into a sentence.
