The current and past price of gasoline.

Step 1: Determine the current and past price of gasoline. Explanation: The price of gasoline is determined at the intersection of the supply curve and demand curve for the product. To find the current and past prices of gasoline, we can look at the website of the Energy Information Administration. Step 2: Look up the current retail price of gasoline. From the website, we can identify that the current retail price of gasoline per gallon is $\mathrm{2.533.}Step3:Findthepriceofgasolineoneyearago.Wecanalsoeasilyidentifythepriceofgasolineoneyearago,whichwas$0.379 per gallon. This price is lower than the current retail price. Step 4: Calculate the increase in price. By subtracting the price of gasoline one year ago from the current retail price, we can determine that the price has increased by $0.379 per gallon in a one-year period. Explanation: The increase in price could be due to variations in either the supply curve of gasoline, the demand curve of gasoline, or both.