To change the default tick marks for the axis of an interval variable:
Open the Hurricanes data set, and create a scatter plot of wind_kts versus latitude.
The scatter plot appears. (See Figure 10.1.) Note that the latitude axis has only a few tick marks. You might decide to add a few additional tick marks.
Figure 10.1: A Scatter Plot

Right-click the horizontal axis of the plot, and select from the pop-up menu, as shown in Figure 10.2.
The Axis Properties dialog box appears, as shown in Figure 10.3. This is a quick way to determine the anchor location, tick unit, and tick range for an axis.
Figure 10.3: Axis Properties Dialog Box

Change the Major tick unit value to 10.
Change the Anchor tick value to 0.
Change the Number of minor ticks value to 1.
Click .
The latitude axis updates, as shown in Figure 10.4.
Figure 10.4: A Scatter Plot with Custom Tick Marks
