Match the vocabulary to the proper definition.
two quantities that increase or decrease (change) by the same factor; also known as directly related
a method of paying someone based on a percentage of their sales
a small amount of money given for a service
the rate of change in a direct variation; also known as the constant of proportionality
multiplying diagonally across the equal sign in a proportion
commission
cross multiplication
directly proportional
constant of variation
gratuity (or tip)
