A research team intends to analyze the opinion of college students across the U.S. regarding a new enacted education rule. This team will have difficulty collecting data from 20 million existing college students, therefore it decides to take a random sample of the population by using 6,000 students.

The team looks at the different attributes of the sample participants and wonders if there are any differences in students' point of view regarding this rule and their major. Assume the team researches the demographics of college students in the U.S. and finds the percentage of what students major in: 8% major in English, 20% major in science, 25% major in computer science, 22% major in engineering, 10% major in mathematics and 15% in other majors.

1. Among different described types of samples in class, what do you recommend for taking those 6000 samples in this case? Please describe the details of how to structure this sampling; i.e. what sampling type(s) to use and how to structure it by conducting necessary calculations, and the reason for choosing that.
2. One sampling frame that the research team can use is the list of CSUN students and selecting 6000 samples from this list. What is at least one possible disadvantage of such a sampling frame?
3. What do you suggest as some suitable data collection methods; e.g. phone interview, for your described sampling process/structure in part "a"? Please justify your selection.