A statistics teacher has 4 periods of introductory statistics. She wants to get students’ opinions on a new homework policy. To get a sample, the teacher lists every student’s ID number and uses a computer to randomly select 20 of the IDs. Which sampling method was used?

The teacher uses a computer to randomly select 20 IDs from a list of all students, giving each student an equal chance of being chosen. This is simple random sampling. Cluster sampling would select whole groups, while stratified sampling would divide students into subgroups before selecting from each.

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