Final answer:
The question cannot be answered without the actual COLI dataset for the regions in question. Typically, one would look at statistical measures like range, variance, or standard deviation to find the region with the least variation in the Cost of Living Index (COLI).
Step-by-step explanation:
The question revolves around the concept of the Cost of Living Index (COLI), which is a type of index number. The COLI is used to compare the relative cost of living between different geographic regions and is based on a variety of expenses, including housing, utilities, grocery items, transportation, health care, and miscellaneous goods and services. The nation's average is set at an index of 100. To determine which region has the least variation in COLI, we would typically analyze statistical measures such as range, variance, or standard deviation. However, the actual dataset containing the COLI scores for the different cities is not provided in the question. As such, without the data, it is not possible to answer which region has the least variation or spread in COLI.
Inflation measures like the Consumer Price Index (CPI) and the core inflation index are closely related to the cost of living, as they track changes in the price level of a basket of goods and services over time. The CPI, calculated by the U.S. Bureau of Labor Statistics, is the most commonly cited measure of inflation and represents the average consumer's purchases. Additionally, measures such as the Employment Cost Index and the GDP deflator serve as broader indicators of inflation within an economy.