A college administrator wants to survey 250 students that attend her college to see if students are satisfied with the course offerings. For the strategies below give appropriate sampling techniques.
1. The administrator stands by the front door of the admissions department and asks the first 250 students who walk in.
2. The administrator researches the ethnic make-up of the college and makes sure that the proportion of each ethnic group represented in the sample is the same as the corresponding proportion of that ethnic group at the college.
3. The administrator goes into 9 classes from many subject areas and asks all the students in each of these 9 classes.
4. The administrator gets the complete list of students at the college and then uses a computer to randomly select 250 students. She then surveys these 250 students.
5. The administrator gets the complete list of students at the college and surveys every 50th students on the list.