Currently, there are 4612 colleges in the United States, and the number of full-time students is 13,203,477.
a. Are the numbers of full-time students at different colleges discrete or continuous?
b. What is the level of measurement for the numbers of full-time students at colleges? (Nominal, ordinal, interval, ratio)
c. What is wrong with surveying college students by mailing questionnaires to 10,000 of them who are randomly selected?
d. If we randomly select 50 full-time college students in each of the 50 states, what type of sample is obtained? (Random, systematic, convenience, stratified, cluster)
e. If we randomly select four colleges and survey all of their full-time students, what type of sample is obtained? (Random, systematic, convenience, stratified, cluster)