What type of rate has a denominator of 1?

A unit rate is defined as a rate that has a denominator of 1, meaning it expresses how much of one quantity corresponds to one unit of another quantity. For example, if you have a speed of 60 miles per hour, this is a unit rate because it tells you how many miles are traveled in one hour.

Unit rates are often used to simplify comparisons between different rates, making it easier to understand the cost per item, speed per hour, or any other measurement where expressing a quantity in terms of one unit provides clarity. The concept of a unit rate is foundational in mathematics, especially in solving real-world problems related to proportions, ratios, and averages.

In contrast, other options like proportion, ratio, and average rate do not strictly adhere to this definition. A proportion compares two quantities, a ratio expresses the relationship between two numbers, and an average rate typically involves summing multiple rates over a period rather than expressing one specific rate in terms of a denominator of one.