Classifying data by setting a predefined classification method

Steps:

1. Right-click the geostatistical layer in the ArcMap table of contents that you want to classify and click Properties.
2. Click the Symbology tab.
3. Click Classify.
4. Click the Method arrow and choose a classification method.
5. Click the up/down arrows on the Classes input box to set the desired number of classes.
6. Click OK on the Classification dialog box.
7. Click OK on the Layer Properties dialog box.