TRENTON, N.J. (AP) — Gas prices dipped in New Jersey and around the nation as a whole amid a drop in crude oil prices. AAA Mid-Atlantic says the average price of a gallon of regular gas in New Jersey on Friday was $3.29, down a penny from last week. Drivers were paying $4.26 a gallon on average a year ago at this time. The national average price for a gallon of regular gasoline was $3.45, down two cents from last week. Drivers were paying $4.28 a gallon on average a year ago at this time. Analysts say the cost of oil accounts for 55 percent of what drivers pay at the pump, but it will take time for the oil price plunge to be reflected in prices at the pump because gas stations paid for the fuel in their underground tanks weeks ago when oil was nearly $15 more per barrel.