The national average price of gasoline fell 7.3 cents to $2.821 per gallon for the week ending Nov. 24, according to federal data.

The cost of gasoline has been falling since late June and has reached a four-year low. It now costs 47.2 cents less than it did a year ago, the U.S. Department of Energy reported.

For the week, the average price fell in nine regions. The sharpest decline came in the Midwest, where the average price fell 9.4 cents to $2.762 per gallon. The Gulf Coast remains the region with the cheapest gas at $2.593 per gallon.

Gasoline costs at least $3.50 per gallon in only Hawaii ($3.907). It costs less than $3 per gallon now in 38 states. South Carolina remains the best deal for gasoline at $2.573 per gallon. Texas gasoline al remains cheap at $2.605 per gallon, according to AAA's Daily Fuel Gauge Report.

Meanwhile, the average price of diesel fuel fell 3.3 cents to $3.628 per gallon. Diesel now costs 21.6 cents less than it did a year ago.