<P> In mathematics, two variables are proportional if there is always a constant ratio between them . The constant is called the coefficient of proportionality or proportionality constant . </P> <Ul> <Li> If one variable is always the product of the other variable and a constant, the two are said to be directly proportional . x and y are directly proportional if the ratio y / x is constant . </Li> <Li> If the product of the two variables is always a constant, the two are said to be inversely proportional . x and y are inversely proportional if the product xy is constant . </Li> </Ul> <Li> If one variable is always the product of the other variable and a constant, the two are said to be directly proportional . x and y are directly proportional if the ratio y / x is constant . </Li> <Li> If the product of the two variables is always a constant, the two are said to be inversely proportional . x and y are inversely proportional if the product xy is constant . </Li>

What does constant of proportionality mean in math terms