PHOENIX (AP) -- Gasoline prices around Arizona are slightly lower at the pump this week. Officials with Triple-A Arizona said Thursday that the average statewide price for unleaded regular gasoline is $3.13 a gallon. That's down by nearly 2 cents from last week. This week's national average is at $3.21 per gallon, more than 4 cents lower than previous week. Tucson has Arizona's lowest average gasoline price at $3.04 a gallon and Flagstaff has the highest at $3.34. Missouri has the lowest average gas prices in the continental U.S. at $2.87 a gallon with Connecticut having the highest at $3.66 a gallon.