sesquiduplicate

Ses`qui*du"pli*cate, a. Etym: [Sesqui- + duplicate.] Defn: Twice and a half as great (as another thing); having the ratio of two and a half to one. Sesquiduplicate ratio (Math.), the ratio of two and a half to one, or one in which the greater term contains the lesser twice and a half, as that of 50 to 20.

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