question: What is the average land area with a density of 815.48, and a Population larger than 411?
answer: SELECT AVG(land_area__hectares_) FROM table_name_29 WHERE density__inh_km²_ = 815.48 AND population > 411
context: CREATE TABLE table_name_29 (land_area__hectares_ INTEGER, density__inh_km²_ VARCHAR, population VARCHAR)