What is a characteristic of rational subgroups in sampling?

The characteristic of rational subgroups in sampling is that they exhibit small variation within the samples and high variation between different samples. This implies that when you take multiple samples (or subgroups) from the population, the observations within each subgroup should be relatively consistent (low variability). However, when comparing these subgroups to one another, there should be significant differences (high variability) between them.

This concept is important in quality control and process improvement as it allows analysts to identify variations within a process that may indicate instability or shifts in performance. By focusing on the differences between subgroups, analysts can draw conclusions about the overall quality and variability of the population, making it easier to pinpoint areas requiring attention or adjustment.

The other characteristics associated with different options do not align with the nature of rational subgroup sampling.