1. Based on a study of 2121 children between the ages of one and four, researchers at the Medical College of Wisconsin concluded that there was an association between iron de?ciency and the length of time that a child is bottle-fed (Milwaukee Journal Sentinel, November 26, 2005). Describe the sample and the population of interest for this study.
2. The student senate at a university with 15,000 stu- dents is interested in the proportion of students who favor a change in the grading system to allow for plus and minus grades (e.g., B+, B, B-, rather than just B). Two hundred students are interviewed to determine their attitude toward this proposed change. What is the population of interest? What group of students constitutes the sample in this problem?