Which of the following is a methodology in which the premium for all of an insurer's covered insureds within a geographic region is the same?

Compound interest refers to the interest calculated on the initial principal and also on the accumulated interest from previous periods. It is a financial concept related to investment growth and does not pertain to insurance premium methodologies. As such, it is irrelevant to the question regarding insurance premium structures.

Experience rating involves setting premiums based on the specific claims history and risk profile of an individual or organization. Unlike community rating, which applies a uniform rate to all insureds, experience rating results in varying premiums based on the individual risk factors, making it the opposite of the methodology in the question.

Concurrent review is a process used in healthcare management to assess the necessity and appropriateness of ongoing medical services. This methodology focuses on evaluating patient care rather than determining insurance premiums. It does not address how premiums are calculated for insured individuals across a geographic region.