Given positive integers a, b, c, d(adsbygoogle = window.adsbygoogle || []).push({});

and for fractions a/b and c/d,

it seems that ( a + c )/( b + d ) is between a/b and c/d.

There's likely an easy proof of this. I'd like to know if there's a formal name for ( a + c )/( b + d ) or the operation that brings it about.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Intermediate ratio

**Physics Forums | Science Articles, Homework Help, Discussion**