Meaning of RATIO in English
/ ˈreɪʃiəʊ; NAmE -oʊ/ noun
( pl. -os ) ratio (of A to B) the relationship between two groups of people or things that is represented by two numbers showing how much larger one group is than the other :
What is the ratio of men to women in the department?
The school has a very high teacher-student ratio.
The ratio of applications to available places currently stands at 100:1.
mid 17th cent.: from Latin , literally reckoning , from rat- reckoned, from the verb reri .
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005