The purpose of using stratified random sampling is to guarantee that the ______________.
a. proportions within the samples represent the proportions in the population.
b. sampling variability is increased
c. sample groups are highly varied for more precise outcomes
d. sampling frame is defined
The purpose of using stratified random sampling is to guarantee that the proportions within the samples represent the proportions in the population. This means that the different strata or subgroups within the population are represented proportionally in the sample.
To implement stratified random sampling, you would first divide the population into distinct and non-overlapping strata based on certain predetermined criteria or characteristics. For example, if you were conducting a survey on a college campus, you could divide the population into different strata such as undergraduate students, graduate students, and faculty members.
Once the strata are defined, you would then randomly select individuals from each stratum to form your sample. The number of individuals selected from each stratum would be proportional to the size or importance of that stratum within the overall population.
By doing so, stratified random sampling ensures that each stratum has representation in the sample, which allows for more accurate estimation of population parameters. This is particularly useful when there are significant differences between the strata, as it allows for the specific characteristics and proportions within each stratum to be adequately captured in the sample.