Necessary pedantry: if he's 4 foot 6 inches now, 3 inches is 5.555 (recurring) percent of that. If he grows at 105.555% per year then by 17 he is a fairly plausible 6 foot 6. (I think he then passes the forty foot mark soon after age 50.)
Ah, but he only grew about half an inch from 9 to 10, so the "rate" of "runaway progress" is "accelerating" "exponentially" (wait, how many derivatives is that?), and he will soon EsCapE CoNTaiNmEnT and hack HuggingFace...
Ah, but he only grew about half an inch from 9 to 10, so the "rate" of "runaway progress" is "accelerating" "exponentially" (wait, how many derivatives is that?), and he will soon EsCapE CoNTaiNmEnT and hack HuggingFace...