To convert gallons to liters, you can use the conversion factor that there are approximately 3.8 liters in 1 gallon.
To find out how many liters of gasoline Julie purchased, you multiply the number of gallons by the conversion factor:
\[ \text{Liters} = \text{Gallons} \times \text{Liters per Gallon} \]
Substituting the values:
\[ \text{Liters} = 15.4 , \text{gallons} \times 3.8 , \text{liters/gallon} \]
Now, calculate the multiplication:
\[ \text{Liters} = 15.4 \times 3.8 \]
Performing the multiplication:
\[ \text{Liters} = 58.52 \]
Therefore, Julie purchased approximately 58.52 liters of gasoline.