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Railways PYQCBT 1 2016

RRB NTPC · Question 63

The variance of a set of data is 144. Then the standard deviation of the data is: A. ±12 B. 12 C. 44 D. 72

  1. A

  2. B

  3. C

  4. D

Show answer & explanation

Answer: (B) B

Explanation

Standard deviation is the positive square root of variance: √144 = 12. It cannot be negative, so ±12 is wrong.