Tracking Trends and Making Forecasts
Plotting a Best-Fit Trendline
If you want to get a sense of the overall trend displayed by a set of data, the easiest way is to use a chart to plot a best-fit trendline. This is a straight line through the chart’s data points where the differences between the chart points that reside above the line and those that reside below the line cancel each other out.
A best-fit trendline is an example of regression analysis, which is a statistical tool for analyzing the relationship between two phenomena, where one depends upon the other. For example, housing sales depend upon interest rates. In this case, you would say that housing sales are the dependent variable and interest rates are the independent ...