What type of random sampling method does Walmart use when they list all their stores based on their location and randomly select a set number from each state?

The sampling method described involves dividing the population of Walmart stores into distinct groups based on their location—specifically, by state—and then randomly selecting a certain number of stores from each of these groups. This aligns perfectly with the characteristics of stratified sampling.

In stratified sampling, the population is first segmented into different strata or groups that share a specific characteristic—in this case, geographical location (states). By randomly selecting from each stratum, the sample can more accurately reflect the diversity and distribution of the overall population. This method is particularly effective when researchers want to ensure representation from various subgroups within the population.

Walmart’s approach enhances the reliability of their findings by acknowledging that stores in different locations may experience different circumstances or trends, allowing them to analyze data in a way that captures these variances efficiently.