How can a trend line be added in Power BI?

A trend line in Power BI is a useful feature that helps to visualize the overall direction and pattern of data points in certain types of charts. The correct approach to add a trend line involves using scatter or line charts because these visualizations naturally illustrate relationships and trends over time or between variables.

In scatter charts, a trend line can help identify correlations between two numerical values, while in line charts, it shows the progression of values over continuous periods, making it easy to observe upward or downward trends. This is important for data analysis, as it enables users to make more informed predictions and decisions based on historical patterns.

The other choices, while relevant to data visualization in Power BI in different contexts, do not pertain to adding a trend line. The analytics pane does not support trend lines in pie charts, a separate data table does not contribute to visualizing trends directly, and visual filters are utilized for data filtering rather than adding trend lines. Thus, the ability to add a trend line specifically pertains to the functionality of scatter and line charts, making that the correct answer.