Cathy conducted a survey on the relationship between substance abuse and average annual income of an individual. She divided the annual incomes into three ranges, labelled them as low income, middle income, and high income, and found the groups to be present in the target population in the ratio of 4:5:1. Cathy needed a sample of 100 participants. She selected 40, 50, and 10 people from each income group in a manner such that each individual in a subgroup had equal chance of getting selected into the respective subsample. Which of the following sampling techniques has Cathy used in this scenario?
A) Stratified random sampling
B) Convenience sampling
C) Cluster sampling
D) Quota sampling

Question

Quizplus · Accepted Answer

Cathy divided the target population into three income ranges (strata) and selected a sample from each stratum in proportion to its presence in the population. This is an example of stratified random sampling, which ensures that each stratum is well-represented in the sample and reduces sampling error. Convenience sampling, cluster sampling, and quota sampling do not involve dividing the population into strata and selecting a sample from each stratum in proportion to its presence in the population.

Cathy Conducted a Survey on the Relationship Between Substance Abuse