Practice Library
All MCQs
Browse exam-wise, subject-wise, and country-wise MCQs with explanations.
Choose an option to check your answer.
A.
1/6
B.
1/4
C.
4/6
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Correct Answer: A. 1/6
Explanation:
Each of the six faces is equally likely for a fair die.
Choose an option to check your answer.
A.
A continuous area curve only
B.
A survival curve without axes
C.
A geographic map
D.
Separated bars or vertical spikes at discrete outcomes
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Correct Answer: D. Separated bars or vertical spikes at discrete outcomes
Explanation:
A PMF is defined at distinct values rather than across continuous intervals.
Choose an option to check your answer.
A.
Every outcome has equal probability
B.
At least one probability is negative
C.
The probabilities over all possible outcomes sum to 1
D.
The variable must be continuous
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Correct Answer: C. The probabilities over all possible outcomes sum to 1
Explanation:
Total probability across the complete discrete sample space must equal one.
Choose an option to check your answer.
A.
A probability density for a continuous interval
B.
The probability of that discrete outcome
C.
A regression coefficient
D.
A cluster label
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Correct Answer: B. The probability of that discrete outcome
Explanation:
A PMF describes a discrete random variable by listing outcome probabilities.
Choose an option to check your answer.
A.
Both detailed shape and a robust compact summary
B.
Two identical representations
C.
Proof of normality
D.
A direct causal analysis
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Correct Answer: A. Both detailed shape and a robust compact summary
Explanation:
The histogram shows modality and shape, while the box plot highlights quartiles and outliers.
Choose an option to check your answer.
A.
Delete it to improve appearance
B.
Replace it with the mean without disclosure
C.
Hide the corresponding axis region
D.
Retain it and use methods or displays that represent its influence honestly
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Correct Answer: D. Retain it and use methods or displays that represent its influence honestly
Explanation:
Valid observations should not be removed merely because they are inconvenient.
Choose an option to check your answer.
A.
The mean of squared distances from zero
B.
The maximum distance from Q1
C.
The median of absolute distances from the median
D.
The count of values above the mean
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Correct Answer: C. The median of absolute distances from the median
Explanation:
The MAD uses the median as both its center and aggregation mechanism.
Choose an option to check your answer.
A.
A guarantee that no outliers exist
B.
A measure of spread that remains stable under a few extreme values
C.
A method for choosing chart colors
D.
A count of missing variables
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Correct Answer: B. A measure of spread that remains stable under a few extreme values
Explanation:
Robust scale measures such as IQR or median absolute deviation limit outlier influence.
Choose an option to check your answer.
A.
The interquartile range
B.
The range
C.
The variance
D.
The standard deviation
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Correct Answer: A. The interquartile range
Explanation:
The IQR depends only on Q1 and Q3, not the most extreme value.
Choose an option to check your answer.
A.
The sample mean changes with bar width
B.
All bins become categorical
C.
Unequal widths force negative frequencies
D.
Wider bins may contain more observations simply because they cover more range
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Correct Answer: D. Wider bins may contain more observations simply because they cover more range
Explanation:
With unequal widths, bar area rather than height should represent frequency.
Choose an option to check your answer.
A.
A histogram whose tallest bar equals the sample size
B.
A chart containing only category names
C.
A histogram scaled so total bar area equals one
D.
A plot with no bin widths
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Correct Answer: C. A histogram scaled so total bar area equals one
Explanation:
Density scaling accounts for bin width and normalizes total area to one.
Choose an option to check your answer.
A.
Mean necessarily
B.
Variance
C.
Median necessarily
D.
Sample size
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Correct Answer: B. Variance
Explanation:
Identical observations have no deviations from their common mean.
