1630s, "reason, rationale," from Latin ratio "reckoning, numbering, calculation; business affair, procedure," also "reason, reasoning, judgment, understanding," from rat-, past participle stem of reri "to reckon, calculate," also "think" (see reason (n.)). Mathematical sense "relationship between two numbers" is attested from 1650s.
雙語例句
1. In 1978 there were 884 students at a lecturer/student ratio of 1:15.
1978年有884名學生，師生比為1比15。
來自柯林斯例句
2. The adult to child ratio is 1 to 6.
成人與兒童的比例為1比6。
來自柯林斯例句
3. What is the ratio of men to women in the department?
這個部門的男女比例是多少？
來自《權威詞典》
4. The ratio of pupils to teachers was 30 to 1.
學生和老師的比率是30比1.
來自《簡明英漢詞典》
5. The ratio between the two sides is one to four.