There are common ways to notate parameters that are different than the way we notate statistics. In general, parameters are notated with Greek symbols, where statistics are either notated by lower case letters or the same Greek symbol with a hat on it. Here, this symbol called mu represents the mean of a population, while these represent the mean of a sample. Similarly, this Greek symbol called sigma represents the standard deviation of a population, while either of these can be used to represent the standard deviation of a sample. This same pattern continues. Here, you can see common parameters and statistics. You can see the parameter and statistic values for not only the mean and standard deviation but also for the variance, proportions, and the values of coefficients and regression. You’ll see all of these in later lessons in the statistics class. This notation will be consistently used throughout these lessons, as well as beyond this course, in books, blogs, and other use cases.