Let's face it - you and I are likely in public relations because we're not very good at math. We don't often cop to this weakness when asked to deal with financial data, survey results or mathematical analysis. There's one article, in quite blunt bullet form, that sets out the dozens of ways we can mistakenly characterize statistics and arguments of logic:
Professor I.J. Good, "A classification of fallacious arguments and interpretations," Technometrics, Volume 4, Number 1, Pages 125-132, 1962. (made available on the web by the American Statistical Association)
There's also an illustrative thread running on Edward Tufte's forums.