To find out how many liters of gasoline Julie purchased, you can use the conversion factor that there are approximately 3.8 liters in 1 gallon.
First, multiply the number of gallons by the number of liters per gallon:
\[ 15.4 \text{ gallons} \times 3.8 \text{ liters/gallon} = 58.52 \text{ liters} \]
Thus, Julie purchased approximately 58.52 liters of gasoline.