Final answer:
The number of male-female couples cohabiting in the U.S. today is substantial, although an exact number is not provided. Cohabitation has become more common among couples, with 8.1 million unmarried couples in 2011.
Step-by-step explanation:
The number of male-female couples cohabiting in the U.S. today is not provided in the given information. However, the information shows that cohabitation has become more common among couples, and the number of unmarried couples has grown significantly in recent years.
According to the U.S. Census Bureau, there were 8.1 million unmarried couples in 2011, accounting for 10 percent of all opposite-sex couples in the United States.
Cohabitation is a growing option for many couples, and it is likely that the number of male-female couples cohabiting in the U.S. today is substantial.