Inferential statistics is the powerful side of statistics. With descriptive statistics, you can describe a data set. Describing a data set might allow you to understand the data set better. With regression, you use past trends to predict future results. With inferential statistics, you extrapolate information about a sample of the population to make predictions about the entire population.
Excel 2013 offers functions for 14 different types of probability distributions. Each distribution predicts a different shape of the population. The following sections cover the various distributions, but for now, consider the distribution in Figure 14.26