Filed at 6:27 p.m. ET WASHINGTON (Reuters) - Two Midwestern U.S. senators asked the Federal Trade Commission on Friday to investigate the region's soaring gasoline prices and whether consumers are being gouged at the pump. The average national price for regular unleaded gasoline is up 54 cents a gallon from a year ago and the seventh highest on record at $1.66 a gallon, according to the U.S. Energy Department. Fuel costs are up even more in the Midwest, where Senators Herb Kohl, Democrat of Wisconsin and Mike DeWine, Republican of Ohio want to know if oil companies are trying to...