Amount Field Showing Count

Hi:

When I place a dollar amount field into either a "Values" column or "axis" column of a Visualization, it shows a "Count" instead of a dollar value.

Even when I hit the drop-down list to the right of the field, there is no "Sum" selection for me to choose.

How do I fix this field to where it will allow for "Sum" or dollar value instead of "Count"?

Thanks!

John