By Jack PerryPROVIDENCE, R.I. -- Gasoline prices in Rhode Island continue to slide, falling three cents in the last week, AAA Southern New England says. The average price for a gallon of regular unleaded gasoline is $3.709 at Rhode Island stations, according to AAA's weekly survey. The average price has dropped 24 cents over the last four weeks. Rhode Island drivers are nevertheless paying 26 cents more than the national average of $3.449 and and 20 cents more than the $3.509 they were paying at this time last year. AAA's survey found a 33-cent price range, from a low of $3.569 to a high of $3.899.