Given the following:
Which of the following time series models best represents this process?
A. ARIMA(1,1,1)
B. ARMA(1,1)
C. SARIMA(1, 1, 1) x (1, 1, 1)1
D. AR(1)
Show Answer
Correct Answer: D
Explanation: The process is given by \(X_t=\delta+\phi_1X_{t-1}+\omega_t\), so it depends on one lagged value and a white-noise error, with no moving-average term or differencing. This is an AR(1) model.
Question 42
A data scientist trained a model for departments to share. The departments must access the model using HTTP requests. Which of the following approaches is appropriate?
A. Utilize distributed computing.
B. Deploy containers.
C. Create an endpoint.
D. Use the File Transfer Protocol.
Show Answer
Correct Answer: C
Explanation: Create an endpoint, such as a REST API, so departments can send HTTP requests to the model and receive predictions. Distributed computing, containers, and FTP do not by themselves provide this access mechanism.
Question 43
A data scientist wants to digitize historical hard copies of documents. Which of the following is the best method for this task?
A. Word2vec
B. Optical character recognition
C. Latent semantic analysis
D. Semantic segmentation
Show Answer
Correct Answer: B
Explanation: Optical character recognition (OCR) converts scanned images or photographs of printed documents into machine-readable text, making it the best method for digitizing hard copies.
Question 44
Which of the following is a classic example of a constrained optimization problem?
A. The cold start problem
B. The traveling salesman
C. Calculating local maximum
D. Calculating gradient descent
Show Answer
Correct Answer: B
Explanation: The traveling salesperson problem seeks the shortest tour while satisfying constraints such as visiting every city exactly once and returning to the starting city.
Question 45
A data scientist is merging two tables. Table 1 contains employee IDs and roles. Table 2 contains employee IDs and team assignments. Which of the following is the best technique to combine these data sets?
A. INNER JOIN between Table 1 and Table 2
B. LEFT JOIN on Table 1 with Table 2
C. RIGHT JOIN on Table 1 with Table 2
D. OUTER JOIN between Table 1 and Table 2
Show Answer
Correct Answer: B
Explanation: A LEFT JOIN keeps every employee and role from Table 1, while adding the matching team assignment from Table 2 when one exists.
Question 46
A data scientist observes findings that indicate that as electrical grids in a country become more and more connected over time, the frequency of brownouts and blackouts in total decrease, and the frequency of major brownouts and blackouts increase. Which of the following distribution metrics could best be identified?
A. Scale axis magnitudes
B. Kurtosis
C. Skewness
D. Normality
Show Answer
Correct Answer: B
Explanation: Kurtosis measures the heaviness of a distribution’s tails and its propensity for extreme events. An increase in major brownouts and blackouts indicates more frequent extreme outcomes, making kurtosis the best choice.
Question 47
Which of the following describes the appropriate use case for PCA?
A. Dimensionality reduction
B. Classification
C. Regression
D. Recommendation
Show Answer
Correct Answer: A
Explanation: PCA transforms features into a smaller set of principal components that preserve as much of the data’s variance as possible, making it primarily a dimensionality-reduction technique.
Question 48
A data analyst wants to find the latitude and longitude of a mailing address. Which of the following is the best method to use?
A. One-hot encoding
B. Binning
C. Geocoding
D. Imputing
Show Answer
Correct Answer: C
Explanation: Geocoding converts a mailing or street address into geographic coordinates, such as latitude and longitude.
Question 49
A data scientist is clustering a data set but does not want to specify the number of clusters present. Which of the following algorithms should the data scientist use?
A. DBSCAN
B. k-nearest neighbors
C. k-means
D. Logistic regression
Show Answer
Correct Answer: A
Explanation: DBSCAN identifies clusters based on the density of data points and does not require the number of clusters to be specified in advance. K-means requires a chosen cluster count; k-nearest neighbors and logistic regression are not clustering algorithms.
Question 50
Given matrix
Which of the following is AT?
A.
B.
C.
D.
Show Answer
Correct Answer: C. \(A^T=\begin{pmatrix}1&2&3\\2&1&2\\3&3&1\end{pmatrix}\)
Explanation: Transposing swaps the rows and columns of A.
$19
Get all 82 questions with detailed answers and explanations
Instant download HTML + PDF delivered the moment payment clears.
Secure Stripe checkout we never see or store your card details.
7-day refund if files are defective see our refund policy.
