A feature layer or table must be loaded into ArcMap in order to use this tool.
Select the feature layer or table you wish to process from the drop-down box. The numerical fields from
the table will be listed in the next drop-down box; select the field you wish to summarize. If there
are any selected features/rows you can elect to use only the select set of records by checking the
"Use selected features only" checkbox. Press the OK button and the summed value will be reported
in a textbox, from which it can be copied and pasted into another application.