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NDA 2017
Exam
NDA
Year
2017
Subject
Mathematics
Chapter
Statistics

NDA 2017 · Mathematics · Statistics

The variance of 20 observations is 5. If each observation is...

The variance of 20 observations is 5. If each observation is multiplied by 3 , then what is the new variance of the resulting observations?

Options

  1. A5
  2. B10
  3. C15
  4. D45

Correct answer

D. 45

Step-by-step solution

New variance =k2=k^2 (old variance) =32×5=9×5=45=3^2 \times 5=9 \times 5=45
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