You can create a graduated symbols map using the Layer Properties dialog box.
A graduated symbols map uses equal-interval classification to create graduated color and/or size maps.
Using the equal-interval classification method, the range of attribute values is divided into equal-sized subranges; the features are then classified based on those subranges.
How to make a graduated symbols map:
Click a layer in the legend to make it active.
Click the Layer Properties button.
Click Graduated Symbols.
Click a Field.
Click a number of Classes.
Click a Style.
Click a Start and End Color.
Click a Start and End Size.
Click an entry in the Symbol column to change its color.
Double-click a value in the Label column to select it. Enter a new value.
Click OK to close the dialog box and see the changes.
Tip: For a graduated symbols map, you can change the label of each value by typing a new value in the Label column. Be sure to press Enter after adding each new value.