U.S. markets ended August with their worst declines since 2012 as fears about China and the Fed continued to weigh on investor's minds. Apple (AAPL) and Cisco (CSCO) said they agreed to partner in a deal which helps Apple move further into the enterprise market. As part of the collaboration, Apple devices will work more effectively on corporate networks utilizing Cisco technology. Stocks closed a volatile August with even more losses as fears over the stability of China's market and uncertainty over a Federal Reserve rate hike persisted. Benchmark indexes closed out with their worst monthly loss in more than three years. Crude oil surged to a six-week high on new data that showed U.S. crude production at a lower-than-expected pace. The EIA lowered its production estimates for the U.S. over the first five months of the year by as much as 130,000 barrels a day each month. TheStreet's Keris Lahiff reports from Wall Street.