In finalizing our review on the year's topics, today we revisited samples and random samples. In most situations, it is impractical to survey or analyze every element in a population, so therefore one selects a sample (a subset of the population). It is important that that sample is random, and therefore representative of the population as a whole, otherwise the results may end up being skewed. We then looked at binomial and normal distributions. Normal distributions, when plotted, illustrate the concept of standard deviation nicely.