Final answer:
The likelihood of meeting someone who is a twin with someone of the opposite sex is influenced by the frequency of fraternal twins in the population.
Step-by-step explanation:
In the human population, the likelihood of meeting someone who is a twin with someone of the opposite sex varies depending on several factors. However, fraternal twins (twins that develop from two separate eggs fertilized by two separate sperm) can be of different sexes. Fraternal twins occur when a woman releases multiple eggs and is fertilized by different sperm at the same time. Therefore, the likelihood of meeting someone who is a twin with someone of the opposite sex is influenced by the frequency of fraternal twins in the population.