Open the access database, create-query design-add two tables, confirm in the query design window-right click, select SQL view-paste below.

Select teaching materials. Department ID, average (patient. Age) as the average age.

Join the tsunami of T patient from the right side of T patient. Patient number = Tsunami. Patient ID.

Group by tsunami. Department id;

-Save-Right-click the menu and switch to Design view to see the design of the query.

In fact, when designing in access, you should first establish the association between two tables, and your first diagram has been displayed. Right-click the association row to modify the association properties. Because you are averaging by department, you should select all records that contain tsubscribe, then drag the fields "Department ID" and "Age" into the design window below, right-click any field to select Summary, and then select the columns "Total" and "Department ID".