Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE district (city_population INTEGER, city_area INTEGER)

### Question ###
Find the total population of the districts where the area is bigger than the average city area.

### Accurate SQL ###

SELECT SUM(city_population) FROM district WHERE city_area > (SELECT AVG(city_area) FROM district)