Which sampling method is used when the population is

Solution

• Stratified Random Sampling:  The population is first divided into distinct, non-overlapping subgroups called  strata  that are homogeneous internally (e.g., strata based on income level, region, profession). Then, a simple random sample is drawn  from each stratum . This ensures representation from all important subgroups.
• Contrast:   Cluster Sampling  divides the population into heterogeneous clusters (e.g., city blocks), and a random sample of clusters is chosen, with all members in chosen clusters surveyed.  Systematic Sampling  picks every k-th member from a list.  Convenience Sampling  is non-random and based on ease of access.