Summaries
Summary allows you to generate a
count, average, sum, standard deviation and other features for your data. The Summary
functions are based on how you grouped your data from the Group tab in Report Wizard or inserting a group.
Inserting summaries
Catalog Browser's Summary window is slightly different from the Summary window of Edit Toolbar and Menu.

Select a field for Summary to compute from the Connection or the Formulas directory. Click on the > button corresponding to Sum On.
The next field to be placed must be a field you selected from the Group/Sort or the Group/Sort tab. So if you selected field A and B from table C, you must either put field A or B in the Break By menu. You may do so by finding your field in the Connection or Formula directory and clicking the > button corresponding to the Break By menu.
Last select a function for your field to be summed on. Click here for a descriptive list of Sum Functions. Click the Done button to finish. A menu will pop up for you to name your new Summary. You may also select a previous name under the Summaries drop down menu.

You have already selected the field you want to have summarized. If you want to create a new summary, select a function to use (click here for a listing) and the field you want to the records to be grouped by. Click Insert to place your new summary.
If you had selected a summary field in your report, you will be given the option to reinsert that same field from the Select a summary from catalog menu.