Write SQL query to solve given problem: How many research assistants of Ogdon Zywicki have an average salary?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT COUNT(T1.prof_id) FROM RA AS T1 INNER JOIN prof AS T2 ON T1.prof_id = T2.prof_id WHERE T2.first_name = 'Ogdon' AND T1.salary = 'med' AND T2.last_name = 'Zywicki'