NEW YORK — A measure of U.S. manufacturing activity plummeted to its lowest level in 26 years in October as the credit crisis and Hurricane Ike disrupted businesses from plastics companies to lumberyards. The reading of 38.9 reported today by the Institute for Supply Management was the worst reading since September 1982. Any reading below 50 signals contraction. For the full story visit www.latimes.com/business/la-fi-econ4-2008nov04,0,5794578.story