Displaying a Linear Trendline

To display a linear trendline for the graph, navigate to the Marks menu, and select Display linear trendline.

display trendline

Note that the trendlines appear on the visual. To see the specific values related to the calculation of the trendline, hover your mouse over the trendline and examine the information in the Tooltip window.

Here is a line visual with trendlines.

Line chart for world population: sum(population) on Y axis, year on X axis, country generating different upward trending lines, calculated trend lines as dashed lines, matching colors, two tooltips showing calculations for trendline and country 'China', to 3 decimal places
Line Chart with Trendlines with Tooltips

Here is a bar visual with trendlines.

Stacked bar chart for world population: sum(population) on Y axis, year on X axis, UN subregion generating the bars, calculated trend lines as dashed lines, matching colors, two tooltips showing calculations for trendline and UN subregion 'Southern Asia'
Stacked Bar Chart with Trendlines Showing, and Tooltips for Southern Asia UN Subregion