Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
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Correct Answer: A. The ordering and timing of observations carry information
Explanation:
Time-series observations are indexed by time and are often dependent across periods.
Reordering them can destroy meaningful temporal structure.
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Correct Answer: D. It provides a nested structure without requiring one fixed k at the start
Explanation:
The dendrogram allows several levels of grouping to be explored after fitting.
However, distance, linkage, and scaling still strongly affect results.
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Correct Answer: C. A dissimilarity or distance matrix
Explanation:
Hierarchical clustering relies on pairwise proximity information.
The choice of distance should match variable types and analytical goals.
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Correct Answer: B. By cutting the tree at an appropriate height
Explanation:
A horizontal cut separates branches into distinct groups.
The height or desired cluster count determines the resulting partition.
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Correct Answer: A. The average pairwise distance between observations in two clusters
Explanation:
Average linkage balances the nearest- and farthest-pair approaches.
It uses all cross-cluster pairs in its dissimilarity calculation.
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Correct Answer: D. The largest pairwise distance between their observations
Explanation:
Complete linkage merges clusters based on their farthest pair of members.
It tends to favor compact clusters with limited diameter.
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Correct Answer: C. Chaining through sequences of nearby observations
Explanation:
Single linkage uses the closest pair of points between clusters.
This can connect elongated groups through narrow bridges.
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Correct Answer: B. A rule for measuring dissimilarity between clusters
Explanation:
Linkage determines how pairwise point distances are summarized between groups.
Different criteria can produce different cluster structures.
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Correct Answer: A. The sequence and dissimilarity levels of hierarchical cluster merges
Explanation:
A dendrogram is a tree representation of nested cluster relationships.
Merge height indicates the dissimilarity at which groups combine.
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Correct Answer: D. It starts with one cluster and repeatedly splits it
Explanation:
Divisive methods work from the top of the hierarchy downward.
Each step divides an existing group into smaller clusters.
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Correct Answer: C. It treats each observation as its own cluster
Explanation:
Agglomerative clustering begins with singleton clusters.
It repeatedly merges the closest clusters until a hierarchy is formed.
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Correct Answer: B. The algorithm will create clusters even when no meaningful grouping exists
Explanation:
Partitioning is guaranteed for any chosen k, but substantive clusters are not.
Stability, visualization, and domain relevance should be evaluated.
