Final answer:
The student's question asks to identify a method used for obtaining a sample, which pertains to different types of sampling methods within Mathematics. These include random, stratified, systematic, cluster, and convenience sampling, each having unique characteristics and applications.
Step-by-step explanation:
The student's question relates to the different methods used for obtaining samples in statistical studies, which is a topic within the field of Mathematics. The four main types of sampling methods discussed are random sampling, stratified sampling, systematic sampling, and cluster sampling. An additional method, convenience sampling, is a non-random sampling method that is often used when other methods are impractical but comes with the potential for biased data.
For example, a stratified sample is obtained by dividing the population into groups called strata before sampling within them, allowing for representation across different segments of the population. Cluster sampling involves dividing the population into clusters, then randomly selecting some to include all members from those clusters. As for convenience sampling, it is based on ease of access to the sample, which can lead to less scientifically reliable data compared to methods based on probability and random selection.