Answer:
Range does not measure the spread of the majority of values in a data set.
Step-by-step explanation:
We are asked to tell why the range might not be the best estimate of variability.
We know that range is the difference between the upper data and lower data point of a data set.
We know that variability determines the spread of a data.
When a data set has large values data outliers, then it will affect the spread.
Let us take an example of the following data set.

The range of the data would be
, while all the data points except 201 are 1 away from each other.
Since range does not measure the spread of the majority of values in a data set, therefore, the range is not the best estimate of variability.