Question

A stratified sample is particularly useful approach when:

a. there is considerable variation between the various strata but relatively little variation within a given stratum.
b. there is no variation between the various strata but relatively big variation within a given stratum.
c. there is considerable variation between the various strata but relatively big variation within the given stratum.
d. none of the above

Answer 1

Stratified sampling is most effective when there is high variation between strata but low variation within them, ensuring each stratum is properly represented.

Step-by-step explanation:

A stratified sample is a particularly useful approach when option (a) is the case, which is when there is considerable variation between the various strata but relatively little variation within a given stratum. This allows for a more representative sample to be obtained, ensuring that each stratum is adequately reflected in the sample. On the contrary, stratified sampling would be less effective when the variation within strata is high, as the distinct characteristics of each stratum would not be as clear.