Capacity Planning - The Practice of Cloud System Administration - page 376

Regression analysis results in a correlation coefficient R , which is a number between
-1 and 1. Squaring this number and then multiplying by 100 gives the percentage match
between the two data sources. For example, for the MAU and network utilization figures
shown in Figure 18.2 , this calculation gives a very high correlation, between 96 percent
and 100 percent, as shown in Figure 18.3 , where R 2 is graphed.
Figure 18.2: The number of users correlates well with network traffic.