[ExI] Probability mind benders [was: Psi and EP]

[mail at harveynewstrom.com]

John Clark <jonkc at bellsouth.net> wrote,
> Now I tell you that I have 2 children and one of them is a boy born on a Tuesday.

Ambiguous in english.  Does it mean that only one child is a boy?  At
least one child is a boy?  Only one child is both a boy and born on
Tuesday?  At least one child is both a boy and born on Tuesday?

The people who calculate this "wrong" are mathematically correct for the
question they think they are being asked.  When the question is asked
clearly, nobody calculates it wrong.

This is not an example of non-intuitive statistics.

--
Harvey Newstrom, Principal Security Architect
CISSP CISA CISM CGEIT CSSLP CRISC CIFI NSA-IAM ISSAP ISSMP ISSPCS IBMCP