Final answer:
The concept of Principle of Progression states that a property of higher cost than those in the same area will have its value reduced.
Step-by-step explanation:
The concept of Principle of Progression states that a property of higher cost than those in the same area will have its value reduced. It means that if a particular property is more expensive than the surrounding properties, its value will be negatively impacted and may be reduced. This principle is used in real estate valuation to determine the value of properties based on their location and surrounding properties.