Career Education Corp. announced Tuesday that its CEO would resign after an outside investigation found "improper" practices in the company's determination of job placement rates. The company's third quarter report to the Securities and Exchange Commission said that the review by an outside law firm had found that some of Career Education's health education and art and design schools did not have sufficient documentation to back up job placements, and that 13 of its 49 schools in those fields had failed to meet the placement rate requirements of the Accrediting Council for Independent Colleges and Schools. While a news release did not specifically say so, it appeared that those developments had prompted the resignation of Gary E. McCullough as president and chief executive.