A researcher is investigating the relationship between sleep duration and academic performance in a sixth-form college with 1500 students. The college has 900 female students and 600 male students. The researcher wants to obtain a representative sample of 120 students using stratified sampling.
Which of the following describes the correct procedure for obtaining this sample?
Place the names of all 150015001500 students into a computer database and use a random number generator to select 120120120 students, regardless of their gender.
Divide the students by gender, assign each student a unique number, and use a random number generator to select 727272 female students and 484848 male students.
Divide the students by gender, and select the first 727272 female students and first 484848 male students who volunteer to participate after seeing a poster in the common room.
Obtain an alphabetical list of all 150015001500 students, select a random starting point, and then select every 12th12^{\text{th}}12th student until 120120120 participants are chosen.
644 exam-style questions on OCR A Level Psychology Research methods and techniques. Each one has a worked solution and a mark scheme showing where the marks go.