They vary proportionally if (and only if) the graph of one variable against the other is a straight line through the origin.
a variable
Two quantities are proportional if they vary in such a way that one of them is a constant multiple of the other.
Variable: A letter or symbol used to represent a number or quantities that vary
If, a unit increase in one is accompanied by the same positive increase in the other (whatever the starting value), and when one is zero the other is also zero. In algebraic terms, if x and y are the two variables, and their relationship is given by y = f(x) then the first condition states that dy/dx is a positive constant, say m. Equivalently, the relationship is the linear function, y = mx + c. The second condition then states that the intercept term, c, is zero. Thus the relationship reduces to y = mx.
In mathematics, two quantities are proportional if they vary in such a way that one of them is a constant multiple of the other.
Bar graph
To scale quantities proportionally, you simply multiply or divide the quantity by the scaling factor. For example, if you want to double a quantity, you would multiply it by 2. If you want to scale a quantity by a different factor, you would use that factor in the multiplication or division process accordingly.
A bar graph.
Two quantities are said to be proportional if they vary in such a way that one of the quantities is a constant multiple of the other, or equivalently if they have a constant ratio.
a variable
To divide a recipe for a smaller portion, you can simply reduce the quantities of all the ingredients proportionally. For example, if you want to make half the recipe, use half of each ingredient listed.
Two quantities are proportional if they vary in such a way that one of them is a constant multiple of the other.
Variable: A letter or symbol used to represent a number or quantities that vary
If, a unit increase in one is accompanied by the same positive increase in the other (whatever the starting value), and when one is zero the other is also zero. In algebraic terms, if x and y are the two variables, and their relationship is given by y = f(x) then the first condition states that dy/dx is a positive constant, say m. Equivalently, the relationship is the linear function, y = mx + c. The second condition then states that the intercept term, c, is zero. Thus the relationship reduces to y = mx.
It is called a variable.
In mathematics, two quantities are proportional if they vary in such a way that one of them is a constant multiple of the other.
No, your eyeballs do not grow in size proportionally with the rest of your body as you age.