# Proportionality Equation

A Proportionality Equation is an Equation that equates two Ratio Statements.

## References

### 2009

• (WordNet, 2009) ⇒ http://wordnetweb.princeton.edu/perl/webwn?s=proportion
• S: (n) proportion (the quotient obtained when the magnitude of a part is divided by the magnitude of the whole)
• S: (n) proportion, ratio (the relation between things (or parts of things) with respect to their comparative quantity, magnitude, or degree) "an inordinate proportion of the book is given over to quotations"; "a dry martini has a large proportion of gin"

### 2008

• Dept. of Eduction, University of Irvine. (2009). “CSET Math Glossary."
• proportion. A relationship between two ratios in which the first ratio is always equal to the second.

### 2007

• http://www.isi.edu/~hobbs/bgt-arithmetic.text
• 3. Measures and Proportions. Sets of rational numbers, and hence sets of nonnegative integers, are very important examples of scales. We will focus on sets in which 0 is the smallest element. If e is the "lt" relation between x and y and s1 is a set of numbers containing 0 but no smaller number, then there is a nonnegative numeric scale s with s1 as its set and e as its partial ordering. … Suppose we have two points x and y on a scale s1 which has a measure. Then the proportion of x to y is the fraction whose numerator and denominator are the numbers the measure maps x and y into, respectively. … In more conventional notation, if m is a measure function mapping s1 into a nonnegative numeric scale, then the proportion f of x to y is given by "f = m(x)/m(y)". … Thus, we can talk about the proportion of one point on a numeric scale to another, via the identity measure.
• proportion: an equality of two ratios; e.g.: 5 : 8 = 10 : 16.

### 2003

• "Definition of Ratio.http://mathforum.org/library/drmath/view/63884.html
• This is as much an English language question as a math question, and that makes it very confusing. Words like this are not used as consistently as you might expect, even among math teachers or mathematicians. Merriam-Webster (m-w.com) says ...
• proportion.
• 3 : the relation of one part to another or to the whole with respect to magnitude, quantity, or degree : RATIO
• 4 : SIZE, DIMENSION
• 5 : a statement of equality between two ratios in which the first of the four terms divided by the second equals the third divided by the fourth (as in 4/2=10/5)