Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
Choose an option to check your answer.
A.
It may be a valid rare observation or evidence of a data problem
B.
All outliers are measurement errors
C.
Removing it always improves prediction
D.
Outliers cannot affect summaries
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Correct Answer: A. It may be a valid rare observation or evidence of a data problem
Explanation:
An unusual point can arise from error, novelty, or genuine variation.
Choose an option to check your answer.
A.
The categorical ordering of labels
B.
The sign of the sample mean
C.
The number of missing columns
D.
Tail heaviness and the frequency of extreme observations
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Correct Answer: D. Tail heaviness and the frequency of extreme observations
Explanation:
Kurtosis reflects how much probability lies in the tails relative to a reference.
Choose an option to check your answer.
A.
A single sharp central peak
B.
A long right tail only
C.
Approximately equal frequency across intervals
D.
Two separated peaks
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Correct Answer: C. Approximately equal frequency across intervals
Explanation:
A uniform distribution assigns similar probability across its support.
Choose an option to check your answer.
A.
Unimodal
B.
Bimodal
C.
Uniform
D.
Degenerate
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Correct Answer: B. Bimodal
Explanation:
A bimodal distribution has two prominent modes or peaks.
Choose an option to check your answer.
A.
How observations are arranged across their possible values
B.
Only the number of variables
C.
The name of the dataset
D.
The file size in memory
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Correct Answer: A. How observations are arranged across their possible values
Explanation:
Distribution shape includes symmetry, skewness, modality, gaps, and tail behavior.
Choose an option to check your answer.
A.
The icon area remains unchanged
B.
The category count is halved
C.
The axis becomes logarithmic
D.
The icon area becomes four times as large
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Correct Answer: D. The icon area becomes four times as large
Explanation:
Scaling both dimensions doubles the area twice, producing a fourfold visual increase.
Choose an option to check your answer.
A.
A pie chart with a trend line
B.
A table without values
C.
A box plot overlaid with jittered points
D.
A map with no geographic variable
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Correct Answer: C. A box plot overlaid with jittered points
Explanation:
The box plot summarizes center and spread, while points reveal sample size and detail.
Choose an option to check your answer.
A.
The labels determine the sample size
B.
Equal visual distances represent ratios rather than equal absolute differences
C.
Logarithms remove all outliers
D.
The axis becomes categorical
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Correct Answer: B. Equal visual distances represent ratios rather than equal absolute differences
Explanation:
Viewers may otherwise interpret spacing as linear.
Choose an option to check your answer.
A.
When positive values span several orders of magnitude
B.
When the data contain only names
C.
When all values are identical
D.
When zero must appear at equal visual intervals
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Correct Answer: A. When positive values span several orders of magnitude
Explanation:
A logarithmic scale compresses large values and expands smaller positive values.
Choose an option to check your answer.
A.
To merge all groups into one average
B.
To eliminate legends from every chart
C.
To convert numeric values to text
D.
To create separate but consistently designed plots for subsets of the data
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Correct Answer: D. To create separate but consistently designed plots for subsets of the data
Explanation:
Facets reduce overlap and allow subgroup patterns to be compared.
Choose an option to check your answer.
A.
A single-variable box plot
B.
A pie chart with one slice
C.
A heat map
D.
A stem-and-leaf plot only
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Correct Answer: C. A heat map
Explanation:
The rows and columns can represent the two categorical dimensions.
Choose an option to check your answer.
A.
A single ordered list only
B.
Values in a two-dimensional matrix or grid
C.
Exact text definitions
D.
A probability model's formula
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Correct Answer: B. Values in a two-dimensional matrix or grid
Explanation:
Heat maps map matrix cells to colors representing magnitude.
