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 table_name_57 ( population INTEGER, municipality VARCHAR, markatal VARCHAR, inhabitants_per_km² VARCHAR )

### Question ###
What is the sum of Population, when Markatal is greater than 48, when Inhabitants Per Km is greater than 24, and when Municipality is Runav k?

### Accurate SQL ###

SELECT SUM(population) FROM table_name_57 WHERE markatal > 48 AND inhabitants_per_km² > 24 AND municipality = "runavík"