Question

Which of the following is the most appropriate unit to describe the rate of the cost of gasoline?

Dollars per gallon, because the dependent quantity is the gallons
Dollars per gallon, because the dependent quantity is the dollars
Gallons per dollar, because the dependent quantity is the gallons
Gallons per dollar, because the dependent quantity is the dollars

Answer 1

Dollars per gallon because the dependent quantity is the dollars

Dollars is the dependent quantity because the amount you pay depends on how many gallons you've pumped.

Answer 2

Dollars per gallon, because the dependent quantity is the dollars.

Explanation:

Dollars is the dependent quantity because it depend on the gallons of gas we have pumped and changes accordingly. The volume of gasoline is an independent variable which price depends on.

A dependent variable is one, who depends on other entities. If the value of one entity changes, the value of the dependent variable also changes.