Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_7 (gdp__ppp__$m_usd VARCHAR, population_density__per_km²_ VARCHAR)
### Question:
How much is the GDP for a population density of 254.7?
### Answer:
SELECT gdp__ppp__$m_usd FROM table_name_7 WHERE population_density__per_km²_ = "254.7"