Laying Out and Formatting a Chart : Formatting axis titles, markers, lines, and labels : Working with an axis title
 
Working with an axis title
Chart types other than pie and meter can have x-axis or y-axis titles. To add and format an x-axis title, you navigate to the X-Axis section of Format Chart. Select Visible, shown in Figure 17‑76. Then, type text in Title. To modify the position, outline, padding, or font style of the axis title, choose Title. Toggle between the x‑axis or the y-axis to make title changes to one or the other by navigating to X‑Axis or Y-Axis in the Chart Area.
Figure 17‑76 Title field and labels in an axis section