What measurement reflects how the average price of a standard group of goods changes over time?

The correct answer is the Price Index, which is a measurement that reflects how the average price of a standard group of goods changes over time. It provides a way to compare the price level of a specific set of products at different points in time, allowing for an assessment of price inflation or deflation.

The Price Index works by taking a selection of goods, often referred to as a "basket of goods," and calculating its total cost during different periods, which reveals changes in purchasing power and cost of living. This index effectively summarizes price movement across this standard group, and it can be adjusted for seasonal variations and other factors to give a clearer picture of price trends.

While other options like the Consumer Price Index are specific types of Price Indices that detail changes in prices of consumer goods and services, the term Price Index, in a more general sense, encompasses a variety of indices that may serve this purpose. Price Indices can include other specialized measures tailored to different sectors or consumer behaviors, making them versatile tools in economic analysis.