WASHINGTON (Reuters) - U.S. business activity increased in October amid strong demand, and firms raised prices for goods and services at the slowest pace in nearly 4-1/2 years, indicating that the economy started the fourth quarter in solid shape.S&P Global said on Thursday that its flash U.S. Composite PMI Output Index, which tracks the manufacturing and services sectors, rose to 54.3 this month from a final reading of 54.0 in September. A reading above 50 indicates expansion in the private sector. Retail sales data has suggested that economic growth gathered more speed in the third quarter.The Atlanta Federal Reserve is currently estimating gross domestic product increasing at a 3.4% annualized rate last quarter. The economy grew at a 3.0% pace in the April-June quarter. The government is scheduled to publish its advance estimate of third-quarter GDP next Wednesday."October saw business activity continue to grow at an encouragingly solid pace, sustaining the economic upturn that has been recorded in the year to date into the fourth quarter," said Chris Williamson, chief business economist at S&P Global Market Intelligence.The survey's measure of average prices charged by businesses for goods and services fell to 51.6, the lowest reading since May 2020, from 54.6 in September. Inflation-weary consumers have been pushing back against higher prices by trading down and buying cheaper substitutes.That was confirmed by the Federal Reserve's "Beige Book" on Wednesday which said reports on consumer spending were mixed in early October, "with some districts noting shifts in the composition of purchases, mostly toward less expensive alternatives."source : investing.com