To determine who paid less for gas, we need to calculate the price per gallon for both Maria and April.

1. Maria's price per gallon: $\frac{22.68}{7.2} = 3.15 \text{ dollars per gallon}$

2. April's price per gallon: $\frac{31.16}{9.5} = 3.28 \text{ dollars per gallon}$

So, Maria paid $3.15 per gallon, and April paid $3.28 per gallon.

Conclusion: Maria paid less for gas because $3.15 per gallon is cheaper than $3.28 per gallon.

Would you like to dive deeper into this, or do you have any further questions?

Here are 5 related questions to extend your understanding:

1. How much would April have spent if she bought the same amount of gas as Maria?
2. How much more did April pay per gallon compared to Maria?
3. What is the total cost for both if they bought 10 gallons each?
4. How would a change in the price of gas affect their total expenses if they bought more gallons?
5. What would the price difference be if Maria bought gas at April's station?

Tip: To quickly compare costs, always divide the total price by the number of units to find the unit price.