Type
Relational Statistical Operator

Purpose
The mean of operator calculates the average value in a specified field in all matching records in a related table. The result can appear as a list item in the detail area of a report or as a statistic in the summary area at the end of each group or at the end of the report.

Syntax
mean of TABLENAME|RELATIONSHIP
[named "UNIQUE RELATIONSHIP NAME" ]
[with ( selection criteria) ] FIELDNAME ;|.

Returns
A numeric value.

Usage
The mean of operator calculates the average of all the values in the specified field (the sum of the values divided by the number of values processed). Blank fields are ignored. Fields that have a value of zero are included in the calculation.
There's an important difference between the statistical operator mean and the relational statistical operator mean of. mean finds the average value in the specified field among the records being processed. mean of finds the average value in the specified field among the records related to the records being processed.

Example
for MEMBERS ;
list records
LAST NAME in order ;
mean of RESERVATIONS TOTAL DUE .
end

This script tells DataEase: (1) Process all the MEMBERS records and list each member's LAST NAME in alphabetical order, (2)for each MEMBERS record processed, find all the related records in the RESERVATIONS table (those that have the same MEMBERID), and (3) list the mean TOTAL DUE for each member from the set of related RESERVATIONS records.
The output from this script might look as follows:

Last Name
Mean of Reservations Total Due
Adams
$2780.00
Albert
$4430.00
Anders
$4055.00
Anderson...
$1910.00...

If you also want to include the mean TOTAL DUE among this group of reservations, change the fourth line of the script to read:

mean of RESERVATIONS TOTAL DUE : item mean .