proportions

In mathematics, two variables are proportional if a change in one is always accompanied by a change in the other, and if the changes are always related by use of a constant multiplier. The constant is called the coefficient of proportionality or proportionality constant. If one variable is always the product of the other and a constant, the two are said to be directly proportional. are directly proportional if the ratio is constant. If the product of the two variables is always equal to a constant, the two are said to be inversely proportional. are inversely proportional if the product is constant. To express the statement, “y is proportional to x,” we write as an equation y = cx, for some real constant c. Symbolically, we write y ∝ x. To express the statement, “y is inversely proportional to x,” we write as an equation y = c/x. We can equivalently write, “y is proportional to 1/x”, which y = c/x would represent. If a linear function transforms into and if the product is not zero, we say are proportional An equality of two ratios such as where no term is zero, is called a proportion.