Final answer:
A rate compares two different unit/measurements, such as 'miles' and 'hour' in the unit rate '55 miles per hour'. It is different from a fraction, which is part of a whole, and a proportion, which is an equation showing equivalent ratios.
Step-by-step explanation:
A rate is a comparison of two different units or measurements. To answer the student's question, a rate compares two different unit/measurements. An example of a rate is '55 miles per hour', which indicates how many miles are traveled in one hour. Here, 'miles' is one measurement, and 'hour' is the second measurement. This is considered a unit rate because the comparison is to one unit of time.
It's important to note that a rate differs from a fraction because a fraction represents a part of a whole (a/b), while a rate indicates how two different types of measurements relate to each other over time. Similarly, a ratio compares two quantities, which could be measurements or numbers, and can be expressed as a fraction, a colon, or using the word 'to', such as 2/3, 2:3, or '2 to 3'. However, a proportion is an equation that relates two equivalent ratios or rates.