Evaluate the Following Generalization(s), Identifying Sample, Population, Attribute of Interest

Evaluate the following generalization(s), identifying sample, population, attribute of interest, and the extent to which the claims involved are knowable. Consider carefully the size and diversification of the sample and the extent to which the population differs or may differ from the sample; remember, what's important is that the sample be representative.
According to a study published by Dr. William P. Newman III of Louisiana State University Medical Center in the New England Journal of Medicine, physicians in Bogalusa, Louisiana, conducted autopsies on thirty-five youngsters ranging in age from seven to twenty-four (the average age was eighteen) who had died mostly from accidents, homicides, or suicides. They found that all but six of the young people had fatty streaks on their aortas, the body's main artery. Fatty streaks are the earliest gross recognizable lesions of atherosclerosis (hardening of the arteries), according to Newman. Since there was a direct link between the number of fatty streaks and the cholesterol levels in the young people, Newman recommended that all schoolchildren be checked for high cholesterol levels.