bcaffo/courses — pull request #4 by TroyOfHelen (2014-05-24 18:48:38+00:00)
Title: fix homework 1 question 1, minus sign and concept

There was a missing minus sign in the explanation. So, the question looked fine, but actually it had a flaw. I checked the forums to be sure there was a mistake. This forum post shows another mistake, that the explanation really fits a different question, where exactly one of the parents has the flu.
https://class.coursera.org/statinference-002/forum/thread?thread_id=180#post-946