<|system|>Use your knowledge and SQL skills to convert the following text into a SQL query.
Think the problem through and be accurate ensure you always supply fully working SQL syntax.

SQL Statments should be wrapped in <codestart type="sql"> and </codeend> tags.

Example output:
<codestart type="sql">SELECT * FROM table_name;</codeend>
<codestart type="sql">SELECT column_name FROM table_name WHERE column_name = 'value';</codeend><|end|><|user|>What is the population in millions for 2011 where the GDP (nominal) (billions USD) is 4? 

SQL Table Create Statement:
CREATE TABLE table_2155836_1 (population__millions VARCHAR, _2011_ VARCHAR, gdp__nominal___billions_usd_ VARCHAR)<|end|><|assistant|><codestart type="sql">SELECT population__millions, _2011_ FROM table_2155836_1 WHERE gdp__nominal___billions_usd_ = "4"</codeend><|end|>