When faced with the question of which of the following would be classified as categorical data, it's important to understand what categorical data means.
Categorical data refers to variables that can be divided into distinct groups or categories. These categories represent different characteristics or qualities, but they do not have a natural order or ranking. Examples of categorical data include eye color, names of cities, or types of animals.
Now, let's go through each of the given options:
1. Number of suitcases on a plane: This is numerical data, specifically a count of items. The number of suitcases is a quantifiable measure that can be ordered and subjected to arithmetic operations.
2. Hair color: This is indeed categorical data. Different hair colors can be categorized (such as blond, brown, black, red), but there is no inherent ranking among these categories.
3. Amount of rainfall: This is numerical data that describes a measurable quantity. Rainfall can be measured in units like millimeters or inches and can be ordered from least to greatest.
4. Tree height: This is also numerical data. Tree height can be measured in feet or meters, and these values can be ordered and compared.
Based on the definitions and the nature of each option, the categorical data among the given choices is:
Hair color
Hence, the correct answer is Hair color.
