Lundberg Survey finds gasoline down 15 cents

CAMARILLO, Calif. (AP) - U.S. gasoline prices continue to fall, dropping an average of 15 cents per gallon over the past three weeks.Industry analyst Trilby Lundberg says the average price of regular is now $3.22 per gallon.The average for midgrade is $3.42. For premium it is $3.57.Of the cities surveyed in the Lower 48 states, the highest average, $3.67 a gallon, was found in San Francisco. The lowest, $2.82, was in Tulsa, Okla.The average price of diesel fuel declined 4 cents a gallon, to $3.87, since the last Lundberg Survey.