NEW YORK -- Wall Street stocks dropped sharply Friday, as fears mounted that interest rates would need to be raised to protect the dollar despite repeated intervention by the Federal Reserve. The Dow Jones industrial average was down 30.44 points at 3,668.65 at 1 P.M., adding to its plunge of more than 125 points since last Friday. It had fallen as much as 50 points earlier. On the broader market, declining issues swamped advances by a more than 4-1 margin on heavy volume of 159 million shares. The Fed, at the direction of the U.S. Treasury and joined by central banks around the world, bought dollars in a concerted move to support the currency after it fell earlier this week to a post-World War II low of less than 100 Japanese yen. At midday, the dollar was at 100.50 yen.