First, we can create a query to pull all received amounts:
  1. Click Queries
  2. Click Manage Queries
  3. Click on a category that you want to store this query in (Ex: Base)
  4. Click New Query under the tasks menu
  5. Name the query
  6. Set the Starting Query to Base/All Constituents
  7. Under Results, set the Data Return Type to Journal Entries
  8. Under Criteria Options mark Match each criteria
  9. Under Browse Fields select Commonly Used Fields from the drop down menu and click on Individual Transaction Received
  10. Fill in Greater Than or Equal to .01
  11. Click Save and Preview

You can then create a report using an aggregate for average:
  1. Click Reports
  2. Click Manage Reports
  3. Click on a category you want to store this report under (ex: System)
  4. Click on New Report under the Task Menu
  5. Name the report 
  6. Under Group Results, select to Group Report By Account and Collapse Groups
  7. Under Browse Fields, select Commonly Used Fields from the drop down and click Account Name and Received
  8. Click on the three dots to the left of the Received column, and select Avg as your Aggregate
  9. Click Save and Run under the Task Menu
  10. Under Query select your category in the top box and your query in the bottom box
  11. At the bottom of the page choose a Delivery Option from the report format drop down box and then click Submit