The price of gasoline in Rhode Island is up four cents this week. AAA Northeast said Monday in its weekly survey that self-serve regular is averaging $2.61 per gallon. That's the same as the national average.The average price of gasoline in Rhode Island is 38 cents higher than it was at this time last year, when it sold for $2.23 per gallon,  an increase of 17 percent. AAA found gas selling for as low as $2.55 per gallon and as high as $2.74 in Rhode Island.