Thursday, February 05, 2009

A maths joke with an econometrics twist

This joke is my own version of a joke to be found in Professor Ian Stewart's excellent book Professor Stewart's Cabinet of Mathematical Curiosities. (I follow the "folk tradition" of adapting songs and stories to fit local conditions and points of reference).

Two mathematicians were having lunch together in a local restaurant. One of them was lamenting the fact that most people in the population are afraid of mathematics, and was wondering what could be done to address the problem. The other mathematician took the view that people actually know more mathematics than they might think, but perhaps don't recognise how much they know. For example, take our waitress. She would immediately know if the tip left for her was generous or not even if she denied having a good understanding of percentages. "Perhaps you are right about that" said the first mathematician "but what about her knowledge of the maths that they teach in school? How much of that do you think she understands? Look, I just need to answer a call of nature, but when I get back maybe we can put it to the test."

While the first mathematician was out of the room the second mathematician called over the waitress. "Look", he said, "when my friend returns I am going to ask you a question. All you have to do is say 'A third of x cubed'. There will be an extra tip for you if you can do this for me."

"Sure. No problem" replied the waitress. "A third ice cube".

"No, no" said the mathematician "A third of x cubed". "OK" , said the waitress "a third of eggs scooped".

"Oh, this isn't going to work" thought the mathematician as he saw his friend returning.

"Ah, good, here's the waitress", said the first mathematician. "Let's test your theory. Just ask her any typical school maths question and we shall see how she can do".

"Right" said the second mathematician, addressing the waitress. "Can you tell me what is the integral of x squared please?".

"Sure" said the waitress." It is one third of x cubed" adding, after a short pause, "plus the constant of integration!".

"Fantastic" said the first mathematician. "Maybe I have been underestimating the general public's maths skills".

"Probably not" said the waitress. "I'm doing a PhD in financial econometrics at the university. I only work here part-time!".