9.22 Are men more promiscuous? Are men more promiscuous by nature than women? Surveys seem to bear this out, with men reporting more sexual partners than women.

On August 12, 2007, the New York Times reported the following.

One survey, recently reported by the U.S. government, concluded that men had a median of seven female sex partners. Women had a median of four male sex partners. Another study, by British researchers, stated that men had 12.7 heterosexual partners in their lifetimes and women had 6.5.

There is one mathematical problem with these results. What is this problem?