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_11647327_2 ( head_of_household VARCHAR, single VARCHAR )

### Question ###
What is the range of the head of household whereas single is $171,551 $372,950?

### Accurate SQL ###

SELECT head_of_household FROM table_11647327_2 WHERE single = "$171,551–$372,950"