How random

Introducing variation will help you model your predictions under other conditions and with other data. But you'll want to know how much variation you are introducing into the data. Recall that we can summarize data with descriptive statistics such as the mean and standard deviation using the AVERAGE(), and STDEV() functions, respectively.

Keep in mind that the average of random positive and negative numbers will be closer to 0. As such, you will also want to know how much absolute variation exists. This is a good opportunity to use the ABS() function to summarize absolute values.