DY0-001 Exam Dumps : CompTIA DataX Exam

→ Linear Discriminant Analysis (LDA) is a supervised classification method used to predict a categorical target (such as travel destination) based on multiple input features. It models decision boundaries between classes — which is appropriate when predicting a fixed set of destinations.

Why the other options are incorrect:

B: k-means is unsupervised and doesn't use labeled output like travel destination.

C: Latent Semantic Analysis is used for extracting relationships from textual data — not categorical prediction.

D: PCA reduces dimensionality but doesn’t classify.

Official References:

CompTIA DataX (DY0-001) Official Study Guide – Section 4.1:“Linear Discriminant Analysis is used when the response variable is categorical and the objective is classification.”

Classification Techniques Guide, Chapter 7:“LDA excels in multi-class prediction when the input data is continuous and the output is a known category.”

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→ A LEFT JOIN ensures all rows from Table 1 (Top Movies) are preserved, even if there’s no matching actor data in Table 2. This matches the requirement to show all movies, enriched with actor information when available.

Why the other options are incorrect:

A: INNER JOIN would exclude movies without matching actor entries.

B: UNION combines distinct rows — not appropriate for matching columns between two tables.

C: INTERSECT shows only common movies — excludes unmatched top movies.

Official References:

CompTIA DataX (DY0-001) Study Guide – Section 5.2:“LEFT JOINs are used when all records from one table (primary) must be retained, even if there are no matching rows in the secondary table.”

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→ The graph represents a classic “elbow curve,” which is often used in clustering (e.g., k-means) to help determine the optimal number of clusters. The point where the curve starts to level off (the “elbow”) reflects the best trade-off between model accuracy and processing efficiency.

In this graph, the elbow visually occurs around k = 10. Beyond that, the processing time continues to decrease, but the marginal gain in clustering quality (or drop in processing time) diminishes.

Why the other options are incorrect:

A: k = 2 underfits the data — too few clusters.

C & D: k = 15 or 20 provides minimal additional benefit in processing but may overcomplicate the model.

Official References:

CompTIA DataX (DY0-001) Study Guide – Section 4.2:“The elbow method identifies the optimal number of clusters where the rate of improvement drops significantly.”

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