Stratified sampling is an appropriate method to use in which of the following circumstances?

Stratified sampling is a statistical sampling technique where the population is divided into subgroups or strata based on certain characteristics. Within each stratum, samples are randomly selected. This method is useful when there are variations within the population that can be grouped into distinct categories.

In the given options:

A. The inspector is examining product from a single lot: In this case, simple random sampling would be more appropriate, as there is no need to stratify the lot.

B. The lot contains product from different machines, production shifts, or operators: This scenario involves different subgroups (machines, shifts, operators), making stratified sampling suitable.

C. The samples are drawn from a continuous flow of product: Continuous flow sampling typically uses other methods (such as systematic or random sampling) rather than stratification.

D. The plan requires samples to be drawn from random containers: Random sampling without stratification would be more appropriate for this situation.

Therefore, option B is the correct choice for using stratified sampling1 .