What is double. Duple ratio (Math.), that in which the antecedent term is double the consequent, as of 2 to 1, 8 to 4, etc called?

duple — Double. Duple ratio (Math.), that in which the antecedent term is double the consequent, as of 2 to 1, 8 to 4, etc. (Webster's 1913.)

Sources