Identify the type of sampling used: systematic, convenience, stratified, cluster, or none of them. Does the sample constitute a random sample?
(a) At a police sobriety checkpoint, every 5th driver is stopped and interviewed.
(b) I randomly select 40 freshmen, 40 sophomores, 40 juniors, and 40 seniors from Champlain College
for a survey on eating habits of our students.
(c) We randomly select one of the 4 sections of statistics and interview all of the students in that class.
(d) In a Gallup poll of 1059 adults, the interview subjects were selected by using a computer to
randomly generate telephone numbers that were then called.
(e) I select the first 5 men in suits and the first 5 men in T-shirts walking down Church Street for a
survey on income.