Which statement identifies the sampling procedure used and gives a valid reason?
Researchers conducted a study on the effects of practice
time of athletes on their endurance.
To form the sample, researchers grouped the population
by sport and then randomly selected 25 athletes from
each group.
O Stratified random sampling: all subjects from each
chosen sport were sampled.
O Stratified random sampling: subjects were randomly
selected from each sport.
O Cluster sampling: all subjects from each chosen
sport were sampled.
O Cluster sampling: subjects were randomly sampled
from each sport.