The number of initial jobless claims fell 8.6% last week, dropping below 400,000 for the first time in months.The Labor Department said the seasonally adjusted figure of actual initial claims for the week ended Sept. 24 decreased by 37,000 to 391,000 from 428,000 the previous week, which was revised upward 5,000.Analysts surveyed by Econoday expected 420,000 new jobless claims last week with a range of estimates between 410,000 and 425,000. Most economists believe weekly jobless claims lower than 400,000 indicate the economy is expanding and jobs growth is strengthening.The four-week moving average, which is considered a less volatile indicator than weekly claims, fell by 5,250 to 417,000 from the prior week's 422,250.The seasonally adjusted insured unemployment rate for the week ended Sept. 17 stayed at 3%, according to the Labor Department.The total number of people receiving some sort of federal unemployment benefits for the week ended Sept. 30 rose to 6.98 million from 6.89 million the prior week.