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_2102945_1 ( archive VARCHAR, viewers__in_millions_ VARCHAR )

### Question ###
When there are 7.5 million viewers what is the archive?

### Accurate SQL ###

SELECT archive FROM table_2102945_1 WHERE viewers__in_millions_ = "7.5"