WGU Foundations-of-Computer-Science Actual Questions

A function definition in Python specifies a function name and a list of parameters. Here, def linear_search(customersList, search_value): defines a function named linear_search that requirestwo argumentswhen called: a list (or sequence) of customer items and the value being searched for. A correct call must therefore supply both arguments in the same order: linear_search(customersList, search_value). Option B is correct because it calls the function properly and then prints the returned result.

Textbooks describe linear search as scanning the list from the beginning to the end, comparing each element to search_value until a match is found or the list ends. The function typically returns an index (e.g., position of the match) or a Boolean, or possibly -1/None if not found. Wrapping the call in print(...) is a standard way to display the returned value for testing or demonstration.

Option A is incorrect because it calls a different function name, not linear_search. Option C is incorrect because linear_search() would attempt to call the function with zero arguments, which would raise a TypeError, and then it tries to call the result as if it were another function. Option D uses a different function name (search_linear) and also contains a spelling mismatch compared to the given definition.

In discrete mathematics and computer science, atreeis a special kind ofgraph. The standard graph-theory definition is that a tree is aconnected, acyclicundirected graph. “Acyclic” means it containsno cycles, i.e., you cannot start at a vertex, follow a sequence of edges, and return to the starting vertex without repeating edges in a way that forms a loop. (Wikipedia) This property is exactly what makes option D correct.

The other options contradict the definition. If a structure has cycles, it is not a tree (though it may still be a graph). If it has unconnected nodes, it is not connected; such a structure is more like aforest(a disjoint union of trees) rather than a single tree. (Wikipedia) The idea of “levels” belongs to a particular computer-science representation called arooted tree, where one node is chosen as the root and nodes can be assigned depths/levels based on distance from the root. But levels are not required in the abstract definition of a tree as a graph; they arise from choosing a root and orientation for convenience in algorithms like BFS/DFS, heaps, and parse trees.

So, the relationship is: every tree is a graph with extra structure—specifically, no cycles and (typically) connectivity—and the “no cycles” rule is the key distinguishing feature. (Discrete Mathematics)

Python list slicing uses the notation list[start:stop], where start is inclusive and stop is exclusive. This means the slice begins at index start and includes elements up to, but not including, index stop. Lists in Python are zero-indexed, so for client_locations = ["TX", "AZ", "UT", "NY"], the indices are: 0 → "TX", 1 → "AZ", 2 → "UT", 3 → "NY".

The slice client_locations[1:3] starts at index 1 and stops before index 3. Therefore, it includes elements at indices 1 and 2, which are "AZ" and "UT". The result is ["AZ", "UT"].

This slice rule is heavily emphasized in programming textbooks because it supports efficient sub-list extraction and is consistent across Python sequence types such as strings and tuples. It also helps avoid off-by-one errors by using an exclusive end boundary. The exclusive stop index makes it easy to take “the first n items” via [0:n] and to split sequences at a boundary without overlap. In practical software development, slicing is widely used for batching data, windowing in algorithms, and parsing structured inputs, making it an essential Python skill.

NumPy arrays are not a built-in Python data structure. In a default Python installation, the interpreter includes core types such as int, float, str, list, tuple, dict, and set, plus the standard library. A NumPy array, typically created as numpy.ndarray, is provided by the third-party NumPy library. Therefore, if a “default Python configuration” does not recognize a NumPy array, the most likely cause is thatNumPy is not installed or not available in the active environment. This happens often when a user has multiple Python environments (system Python, virtual environments, conda environments) and installs NumPy into one environment while running code in another.

Option B is incorrect because Python’s standard-library array module is different from NumPy. Importing array does not create or enable NumPy’s ndarray type. Option C is possible in rare cases,but the typical, textbook-aligned explanation is missing dependencies rather than an incorrectly configured interpreter. Option D is also unlikely: while very old Python versions may cause compatibility issues with modern NumPy releases, the symptom described—NumPy arrays not being recognized at all—more directly indicates the package is absent in the running environment.

In practice, verifying import numpy and checking the installed packages for the current interpreter resolves the issue.