Final answer:
The domain of the function f(x, y, z) consists of all possible majors for X, the set of non-negative integers for Y representing the number of classes, and any non-negative amount of money for Z.
Step-by-step explanation:
The domain of a function f(x, y, z) represents all the possible values that the input variables (x, y, and z) can take. Specifically:
- The domain of X includes all majors such as English and Mathematics, including 'undeclared' - basically, the list of all the majors that the university offers.
- The domain of Y is the set of all non-negative integers representing the number of classes a student could have taken, starting from zero up to the maximum allowed by the school.
- The domain of Z is any non-negative monetary amount, signifying the money spent on books. A value of z = -7 would not be a possible value since one cannot spend a negative amount on books.
X, Y, and Z are considered random variables because their values can vary and are not determined until the data is collected and analyzed.