Final answer:
The domain of a relation is the set of all possible inputs for the relation, while the range is the set of all possible outputs. Domains can be numerical or described in words, and the values are determined by randomness.
Step-by-step explanation:
Complete the sentence about the relation: The domain of the relation is the set of all possible inputs and the range is the set of all possible outputs.
The domain of a random variable (RV) can be numerical or non-numerical, such as descriptive words. For instance, if X = hair color, then the domain is {black, blond, gray, green, orange}.
We can only determine the specific value x that the random variable X takes after an experiment is conducted. Random variables are used because they can represent values that are outcomes of random phenomena.