Practice GAT Subject Statistics questions with answers and explanations.
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Standard deviation is the square root of variance.
Larger values indicate greater dispersion around the mean.
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The IQR measures the spread of the middle 50 percent of data.
It is resistant to extreme observations.
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A z-score gives signed distance from the mean in standard-deviation units.
Positive values lie above the mean.
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The values sum to 28 and there are four observations.
The arithmetic mean is 28 ÷ 4 = 7.
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A discrete variable takes countable values, usually integers.
The number of students cannot meaningfully take fractional values.
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The data are already ordered and contain five values.
The third value is the median, so the answer is 7.
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Continuous variables can take any value within an interval.
Weight can be measured to increasingly fine precision.
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With four ordered observations, average the two middle values.
The median is (4 + 8) ÷ 2 = 6.
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Nominal data classify observations without ranking them.
Examples include blood group and marital status.
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Ordinal data preserve order among categories.
The gaps between successive categories need not be equal.
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Interval scales support meaningful differences between values.
Temperature in degrees Celsius has no true absence point.
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Ratio-scale data support meaningful ratios because zero represents absence.
Weight, distance, and age are common examples.
