Proportional Relationships

Front

What is a proportional relationship?

Back

A proportional relationship is a relationship between two quantities where the ratio of one quantity to the other quantity is constant.

Front

What is the constant of proportionality?

Back

The constant of proportionality is the constant value (k) that relates two proportional quantities, defined as k = y/x.

Front

If the constant of proportionality is k = 2, what does this mean?

Back

This means that for every unit increase in x, y increases by 2 units.

Front

How do you find the constant of proportionality from a table of values?

Back

Divide the value of y by the corresponding value of x for any pair of values; if the result is constant, that value is the constant of proportionality.

Front

If 3 apples cost $6, what is the cost of 5 apples?

Back

$10 (Cost per apple is $2, so 5 apples cost 5 x $2 = $10).

Front

True/False: A proportional relationship can be represented by a straight line through the origin on a graph.

Back

True.

Front

What is the formula to calculate the constant of proportionality?

Back

k = y/x, where y is the dependent variable and x is the independent variable.

Front

If the cost of 10 notebooks is $30, what is the cost of 15 notebooks?

Back

$45 (Cost per notebook is $3, so 15 notebooks cost 15 x $3 = $45).

Front

What does it mean if two quantities are not proportional?

Back

It means that the ratio of the two quantities is not constant; as one quantity changes, the other does not change in a consistent manner.

Front

If a recipe calls for 2 cups of flour for every 3 cups of sugar, what is the constant of proportionality for flour to sugar?

Back

The constant of proportionality is 2/3.