The next descriptive statistics covered will be the mean, also called the average, and standard deviation. In this section, we will use the sum and length functions to compose the mean of a dataset. We'll also explore the sum and length functions; compose our mean function; and then use that mean function in order to compose a standard deviation function. Finally, we're going to compute the mean and standard deviation of the 2015 away-team runs using our function.
The mean is a summary statistic that gives you a rough idea of the middle values of the dataset, while not truly being the middle of a dataset:
