From the question, the population of an high school from which selection was made equals 461 sophomores, 328 juniors and 558 seniors.
35 sophomores, 69 juniors and 24 seniors are randomly selected. The technique used in selecting is Stratified sampling technique. This is because stratified sampling involves dividing the entire population into stratas and then selects a final sample randomly from the different strata. This means that a smaller part of the entire population is used as a sample in drawing conclusions for the entire population.
