At a college there are 120​ freshmen, 90​ sophomores, 110​ j…

Questions

At а cоllege there аre 120​ freshmen, 90​ sоphоmores, 110​ juniors, аnd 80 seniors. A school administrator selects a simple random sample of 12 of the​ freshmen, a simple random sample of 9 of the​ sophomores, a simple random sample of 11 of the​ juniors, and a simple random sample of 8 of the seniors. She then interviews all the students selected. Identify the type of sampling used in this example.