Identify the following sampling schemes. (a) From a group of 400 students, every
ID: 3171504 • Letter: I
Question
Identify the following sampling schemes.
(a) From a group of 400 students, every 24th student starting with the 16th student is
selected.
(b) A school district has 18 elementary schools.An education researcher randomly
selects 2 elementary schools from the district and interviews all the teachers at
each of the two schools.
(c) At a college there are 120 freshmen, 90 sophomores, 110 juniors, and 80 seniors. A school administrator selects a simple random sample of 6 of the freshmen, a simple random sample of 5 of the sophomores, a simple random sample of 6 of the juniors, and a simple random sample of 4 of the seniors. She then interviews all the twenty-one students selected.
(d) A pollster uses a computer to generate 500 random numbers and then interviews the voters corresponding to those numbers.
(e) .An NBC television news reporter gets a reaction to a breaking story by polling people as they pass the front of the studio.
(f) A Johns Hopkins University researcher surveys all cardiac patients in each of 30 randomly selected hospitals.
Explanation / Answer
(a) From a group of 400 students, every 24th student starting with the 16th student is
selected. This is Systematic sampling
(b) A school district has 18 elementary schools.An education researcher randomly
selects 2 elementary schools from the district and interviews all the teachers at
each of the two schools. This is random sampling
(c) At a college there are 120 freshmen, 90 sophomores, 110 juniors, and 80 seniors. A school administrator selects a simple random sample of 6 of the freshmen, a simple random sample of 5 of the sophomores, a simple random sample of 6 of the juniors, and a simple random sample of 4 of the seniors. She then interviews all the twenty-one students selected. This is Stratified Sampling
(d) A pollster uses a computer to generate 500 random numbers and then interviews the voters corresponding to those numbers. This is random sampling
(e) .An NBC television news reporter gets a reaction to a breaking story by polling people as they pass the front of the studio. This is a biased sampling
(f) A Johns Hopkins University researcher surveys all cardiac patients in each of 30 randomly selected hospitals. This is cluster sampling