Average retail gasoline prices have fallen in five consecutive weeks, putting many Americans on track to pay much less for fuel this summer and potentially boosting U.S. consumers at a time when many analysts are projecting a slowdown in economic growth. Gasoline prices dropped as U.S. crude oil, the main raw ingredient in gasoline, fell into a bear market last week, down more than 20% from its April peaks. The average U.S. price for a gallon of regular gas has hit its lowest level in more than two months, figures from price-tracking…