A program exists to encourage more middle school students to major in math and science when they go to college. The organizers o
f the program want to estimate the proportion of students who, after completing the program, go on to major in math or science in college. The organizers will select a sample of students from a list of all students who completed the program. Which of the following sampling methods describes a stratified random sample? (A) Select all female students on the list. (B) Randomly select 50 students on the list. (C) Randomize the names on the list and then select every tenth student on the randomized list. (D) Randomly select 25 names from the female students on the list and randomly select 25 names from the male students on the list. (E) Randomly select 50 students on the list who are attending college.
In the stratified random sample we would divide our population into homogeneous groups / strata and then we randomly select the individuals in each group / stratum.
In general, when comparing with the simple random sample, we realize that stratified random sampling has the advantage of increasing accuracy and decreasing variability.
In the question, we have two strata: female students and male students. On each one of the strata, a random sample of 25 names was made in the list.
