Sonia is a program director for a major health insurance provider. Recently she has been reading in medical journals and other articles, and she found a strong emphasis on the influence of weight, gender, and cholesterol on the development of coronary heart disease. The research she's read confirms time after time that there is a connection between these three variables, and she knows that there are certainly life choices that can be made to alter one's cholesterol and weight. She begins brainstorming ideas for her company to offer weight and cholesterol management programs to individuals who receive health insurance through her employer. As she considers where her efforts might be most effective, she finds herself wondering if there are natural groups of individuals who are most at risk for high weight and high cholesterol, and if there are such groups, where the natural dividing lines between the groups occur so that she can target her efforts towards those insured individuals who stand to benefit the most from a program designed to improve these risk attributes.