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_63 (population VARCHAR, gdp__nominal_ VARCHAR)
### Question:
Which population has a GDP (nominal) of $6.4 billion?
### Answer:
SELECT population FROM table_name_63 WHERE gdp__nominal_ = "$6.4 billion"