Identify the two quantities being compared
Check whether one quantity changes in a constant ratio with the other
Write the relationship as a fraction or equation
Compare corresponding ratios
Verify that all matching ratios are equal
Use cross multiplication to test proportionality
If ( frac{a}{b} = frac{c}{d} ), then the quantities are proportional
If one quantity is a constant multiple of the other, they are proportional
Find the constant of proportionality by dividing one variable by the other
Confirm the same constant applies to all pairs of values