Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
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A.
A bullet chart or compact bar with a clearly marked target
B.
A three-dimensional pie chart
C.
An unlabeled icon array
D.
A rotating animation
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Correct Answer: A. A bullet chart or compact bar with a clearly marked target
Explanation:
Aligned positions and lengths enable accurate comparison with a target.
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A.
It guarantees every hypothesis is correct
B.
It removes the need for source data
C.
It converts all graphs into three dimensions
D.
Code, results, narrative, and graphics can be regenerated together
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Correct Answer: D. Code, results, narrative, and graphics can be regenerated together
Explanation:
Literate documents link explanations directly to executable analysis code.
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A.
save_mean()
B.
write_plot_data()
C.
ggsave()
D.
export_factor()
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Correct Answer: C. ggsave()
Explanation:
ggsave() saves the current or specified ggplot object in formats such as PNG, PDF, or SVG.
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A.
Keep default variable codes without explanation
B.
Use informative titles, axis labels, units, and legends
C.
Remove every tick mark regardless of context
D.
Use unrelated colors for identical meanings
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Correct Answer: B. Use informative titles, axis labels, units, and legends
Explanation:
Labels tell viewers what variables and scales represent.
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A.
The analytical workflow remains transparent and reproducible
B.
Manual edits always improve accuracy
C.
Code prevents all missing values
D.
Plots cannot use transformed data
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Correct Answer: A. The analytical workflow remains transparent and reproducible
Explanation:
Scripted transformations can be inspected, rerun, and corrected.
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A.
Inside removes color, while outside creates a new variable
B.
Inside changes sample size, while outside changes the mean
C.
There is no difference
D.
Inside maps color to data, while outside assigns one fixed color
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Correct Answer: D. Inside maps color to data, while outside assigns one fixed color
Explanation:
Mapped aesthetics vary across observations and usually generate a legend.
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A.
The raw variable values
B.
The fitted distribution parameters
C.
Non-data display elements such as fonts, grid lines, and backgrounds
D.
The number of observations
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Correct Answer: C. Non-data display elements such as fonts, grid lines, and backgrounds
Explanation:
Themes style the presentation without changing the underlying statistical mapping.
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A.
To calculate confidence intervals
B.
To create panels for subsets defined by categorical variables
C.
To merge all categories into one value
D.
To remove the plot axes
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Correct Answer: B. To create panels for subsets defined by categorical variables
Explanation:
Faceting repeats a plot structure across groups.
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A.
The type of graphical mark used to represent observations or summaries
B.
The data file's directory
C.
The significance level
D.
The random-number distribution
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Correct Answer: A. The type of graphical mark used to represent observations or summaries
Explanation:
Geoms include points, lines, bars, box plots, and smooth curves.
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A.
A rule for installing an R package
B.
A test for equal variances
C.
A method for generating random seeds
D.
A rule linking a data variable to a visual property
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Correct Answer: D. A rule linking a data variable to a visual property
Explanation:
Aesthetics include x-position, y-position, color, size, shape, and transparency.
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A.
It guarantees every event time is observed
B.
It increases all survival probabilities equally
C.
Censoring depends on unobserved event risk and can bias survival estimates
D.
It removes the need for assumptions
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Correct Answer: C. Censoring depends on unobserved event risk and can bias survival estimates
Explanation:
Standard survival methods generally assume censoring is independent of event time given relevant information.
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A.
Means of two independent normal variables only
B.
Survival experience between groups over the observed follow-up
C.
Kernel bandwidths
D.
Numbers of histogram bins
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Correct Answer: B. Survival experience between groups over the observed follow-up
Explanation:
The log-rank test compares observed and expected events across risk sets.
