
Observe how the projected Ys in the trend, despite being linear, are close to the known Ys. Excel will fill the cells with the trend values. Now, right-click on any of the points of the chart and select Add Trendline. As a result, you will see a scattered chart of your selected dataset. Then, from the available options select Scatter. Next, go to the Insert tab and click on the Insert Scatter (X, Y) or Bubble Chart dropdown. These new Ys are calculated off the trend line. First, select the dataset with the help of the mouse. Finally, the formula tells TREND that A2 to A11 will be the new Ys. Then it feeds the TREND function cells A2 to A9 as the known Xs.


The goal is to draw a chart of the series, and its trend, using the TREND function. However, we have 10 Ys from 1 to 10, but only 8 Xs which are for the values 1 to 8. In this sample spreadsheet, we have a time series.

Now that you know what the TREND function is and what it does, let's put it to use.
