Answer: Qualitative data set
Explanation:
- The quantitative data deals with numbers and elements we count or measure such as: dimensions such as height, width, and length.
- The qualitative data deals with characteristics and descriptors that can't be counted or measured, but can be observed by its quality such as color, tastes and smell.
The given sentence :- “the hair color of the presidents of the United States”
Since color is express the quality of the hair but not the quantity.
Therefore, the given data set is a qualitative data set.