Microsoft posted second-quarter revenue of $19.95 billion, beating expectations. Results buoyed by the Kinect add-on for Xbox consoles. Amazon fourth-quarter revenue rose 36 percent, to $12.95 billion but fell short of analyst expectations. Yahoo more than doubled its profit to $312 million, mostly through costcutting, but revenue fell 12 percent to $1.53 billion as the company fights to gain momentum against rival Google. Intel boosted its dividend by the biggest gain in five years and added $10 billion to its stock buy-back plans. DuPont reported a 15 percent drop in fourth-quarter earnings, down to $376 million, but raised 2011’s forecast. Ford Motor reported an unexpected slide in fourth-quarter earnings, down 79 percent to $190 million, owing to rising costs in North America and commodities prices. Last year, however, was among its best ever, with $6.6 billion in revenue. American Express said increased spending by its customers drove up its profit 48 percent, to $1.06 billion. Revenue grew 13 percent to $7.32 billion. Halliburton more than doubled its earnings with a fourth-quarter profit of $605 million on improved global results and record U.S. revenue for its efforts to exploit shale formations in North America.