Google Sheets now helps you to see patterns in your data by letting you add trendlines to your charts in Google Sheets. You can add trendlines to scatter plot, line, column, or bar charts.
Take a look at this example scatter plot:
To add a trendline to the chart, I first need to click the down arrow above the chart and select Advanced edit… :
In the Customise tab of the chart edit dialog, I can scroll down and choose either Linear or Exponential types of trendline:
Extra options now open to let me customise how the trendline is displayed:
The displayed trendline will be subsequently recalculated in real time as data is added or modified. Here I’ve added some new data points at the right of the graph, and I can see the trendline visibly change as each point is entered:
To edit your trendline, click the drop-down to return to Advanced edit, or click the trendline itself to edit most options straight from the chart: