ra·tio (rāshō, rāshē-ō′)
n. pl. ra·tios
1. Relation in degree or number between two similar things.
2. The relative value of silver and gold in a currency system that is bimetallic.
3. Mathematics A relationship between two quantities, normally expressed as the quotient of one divided by the other; for example, the ratio of 7 to 4 can be written 7:4 or 7/4. A ratio can often also be expressed as a decimal or percentage.
[Latin ratiō, calculation, from ratus, past participle of rērī, to reckon, consider; see ar- in the Appendix of Indo-European roots.]
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