I had the same problem with MySQL version 8.0.23.
I solved it in the following way:
Opening again the msi installer for windows.
In MySQL Server I clicked on "Reconfigure".
Then I clicked on the following steps until I got to "Accounts and Roles" and there I set the password for "root".
Finally in SQL Workbench, I went to ...
You have 3 tables you need to accomplish this:
Appointment Table, Physician table and little bit of the Specialization table (but just enough to know that the Family Medicine specialization has an specialization ID of 100).
This means your sql is:
select avg(a.appointment_charge) as AvgCharge
from appointment a inner join p on a.physician_id=p.physician_id