In preparation for mathematically formalizing Jared's long-term project, we briefly revisited the standard deviation. In conjunction with this, I introduced the concept of 'margin of error', important when dealing with samples. The margin of error is 1 / sqrt(n), where n is the sample size. This ties in with the Law of Large Numbers – i.e. the larger the sample size, the smaller the margin of error. We worked through some examples to illustrate this. We also discussed what other populations we can bring into the project, and Jared had some excellent ideas.