Final answer:
The given sampling method is an example of simple random sampling because each high school student has an equal chance of being selected, which is a key feature of SRS. Systematic sampling, which was also mentioned, is a different method and does not qualify as SRS.
Step-by-step explanation:
Understanding Simple Random Sampling
The sampling method described, where a completely random method is used to select 75 students and every high school student has the same probability of being selected at any stage, gives each student an equal chance because it adheres to the principles of simple random sampling (SRS). In simple random sampling, each member of the population has an equally likely chance of being selected, and each sample of the same size also has an equal chance of being chosen.
Using a random number generator to select from an alphabetical list and then selecting every 50th student until 75 students are chosen, however, does not constitute simple random sampling. This method is known as systematic sampling, which can have elements of randomness but does not ensure that all possible samples of the same size have the same chance of being selected, thus it is not an SRS.
In contrast, stratified sampling involves dividing the population into strata and taking a proportionate simple random sample from each stratum. Random assignment in experimental designs is crucial to ensure that every participant has an equal chance of being assigned to different groups, further supporting the fairness and validity of the study results.