One of the primary purposes for breaking
data into groups is to find a total for each group of records instead of for
all the records in the report. To find the total, you must summarize the data.
When the program summarizes data, it sorts
the data, breaks it into groups, and then summarizes the values in each group.
It does this all automatically.
Many summarizing options are available.
Depending on the data type of the field you plan to summarize, you can do the
following:
Sum the values in each group.
Count all the values or only those
values that are distinct from one another.
Determine the maximum, minimum,
average, or Nth largest value.
Calculate up to two kinds of standard
deviations and variances.
For example:
Customer list reports: determine the
number of customers in each state. The summary would count the distinct
customers in each state group.
Purchase order reports: determine the
average order placed each month. The summary would calculate the size of the
average order for each month group.
Sales reports: determine the total
sales per sales representative. The summary would sum or subtotal the purchase
order amounts for each sales representative group.
Note: You can also calculate
summary fields across hierarchical groupings: set "Summarize across hierarchy"
to True in the Summary Options section of the Properties view.