In a study of second language learning, Researcher A found that individuals whose parents were bilingual were 2.5 times more likely to be fluent in a second language by age 21 than children whose parents were not bilingual. However, Researcher B read the study and interpreted the results to indicate that children of monolingual parents were 0.40 times as likely to become bilingual by age 21. Why do both researchers have a correct understanding of the study results?