By John S. McClenahen Even as the Federal Open Market Committee was weighing its interest-rate options, the U.S. economy continued to send mixed signals. For the second straight month, retail sales advanced in July, up 1.2% from June to $304.3 billion, says the U.S. Commerce Department. However, July's rise was two-tenths of a percentage point below the revised 1.4% increase in retail sales from May to June. Meanwhile, total new orders for machine tools that cut and form metal fell 1.4% in June to $218.82 million, according to statistics compiled by the American Machine Tool Distributors' Association and AMT -- the Association for Manufacturing Technology. A 7.1% decline to $185.24 million in new orders for metal-cutting machine tools overpowered a 49.7% increase to $33.58 million in new orders for metal-forming tools.