China’s factory activity unexpectedly fell to a five-month low in October as firms fought slowing orders and rising costs in the cooling economy, reinforcing views that the country’s growth outlook is hazy at best. The official Purchasing Managers’ Index (PMI) eased to 50.8 in October from September’s 51.1, the National Bureau of Statistics said on Saturday, but above the 50-point level that separates growth from contraction on a monthly basis.