what can we mean by a range of data set

The difference between the highest and the lowest observation gives us an idea of the
spread of the observations. This can be found by subtracting the lowest observation from
the highest observation. We call the result the range of the observation.

For example: The ages in years of 10 teachers of a school are:
32, 41, 28, 54, 35, 26, 23, 33, 38, 40

Q. What is the range of the ages of the teachers?

Answer: Range of the ages of the teachers = (54 – 23) years = 31 years