US central bank has announced its biggest interest rate rise in nearly 30 years to rein in surging inflation. The Federal Reserve said it would increase its benchmark rate by three-quarters of a percentage point to a range of 1.5 percent to 1.75 percent.<br />'' <br />'' The rise, the third since March, comes after inflation surged unexpectedly last month.<br />'' <br />''It is the largest rate hike since 1994, and will affect millions of American businesses and households, pushing up the cost of borrowing for homes, cars and other loans in order to force a slowdown in the economy.