mean proportional

American  

noun

Mathematics.

1. (between two numbers a andb ) a number x for which a/x = x/b .

   The number 3 is a mean proportional between 1 and 9.

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Etymology

Origin of mean proportional

First recorded in 1565–75

Example Sentences

The perpendicular is the mean proportional between the segments of the hypotenuse.

From The Teaching of Geometry by Smith, David Eugene

Find a mean proportional between 4 and 16; 18 and 50; and 3.

From A Review of Algebra by Rivenburg, Romeyn Henry

If 4 quantities are in proportion and the second is a mean proportional between the third and fourth, prove that the third will be a mean prop. between the first and second.

From A Review of Algebra by Rivenburg, Romeyn Henry

We then find the mean proportional between the length HD and the height of the parallelogram.

From Amusements in Mathematics by Dudeney, Henry Ernest

Then the whole line CZ is 139,655; and CS, which is a mean proportional between CZ and CO will be 93,410.

From Treatise on Light by Huygens, Christiaan