Same chapter3 marksDifficulty: Medium
Why is the standard deviation preferred to the mean deviation as a measure of dispersion?
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3 marksDifficulty: Medium
What is the effect on the mean and the standard deviation of adding a constant to every observation, and of multiplying every observation by a constant?
Original Khojo Papers practice question — not from a past board paper.
Answer
Adding a constant adds it to the mean and leaves the standard deviation unchanged, because every deviation from the mean is unaffected. Multiplying by a constant multiplies both the mean and the standard deviation by that constant.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
This is why the standard deviation is independent of a change of origin but not of scale.
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