Security workers at an airport randomly choose one of the first 50 people to pass through a checkpoint for extra security screening. After that person, they choose every 50^th person who passes through for extra screening as well.

A student council surveys 100 students by taking random samples of 25 freshmen, 25 sophomores, 25 juniors, and 25 seniors.

A researcher polls people as they walk by on the street.

A support hotline asks callers to stay on the line after they have completed their call to respond to a short survey.

A teacher puts students' names in a hat and chooses without looking to get a sample of 3 students.

A truck manufacturer selects 3 trucks at random from each of 6 models for safety testing.

A large bakery mass produces cakes on an assembly line. Each shift, a quality control expert randomly selects one of the first ten finished cakes, and every tenth cake thereafter. Employees weigh those cakes and give the cakes a detailed visual check.

Each student at a school has a student identification number. Counselors have a computer generate 50 random identification numbers, and the students associated with those numbers are asked to take a survey.

A professor asks the first 5 students who arrive to class to participate in a research study about young adult sleep patterns.