Indicate which type of sampling design is being utilized in each of the following scenarios.

1. Obtain a list of all 300 students in an introductory engineering class. Give each student a number 1 through 300. Use a random number generator to randomly select a sample of 25 students.

2. Obtain a list of all undergraduate students at Miami University that are majoring in statistics. Pick a random starting point on the list of students and then select every 20 ^th student until a sample of size 50 is produced.

3. Each 11 ^th grade homeroom in a large high school contains 30 students. Randomly select 5 homerooms and sample every student in that homeroom to get a sample of 150 11 ^th grade students.

4. University undergraduate students can be classified as freshmen, sophomores, juniors, or seniors. Compile a list of all freshmen, sophomores, juniors, and seniors. Randomly select 50 freshmen, 50 sophomores, 50 juniors, and 50 seniors to produce a sample of size 200.