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NTA Abhyas JEE Main2020MathematicsStatisticsPractice

If ∑ i = 1 5 x i - 6 = 5 and ∑ i = 1 5 x i - 6 2 = 25 , then the standard deviation of observations 3 x 1 + 2,   3 x 2 + 2,   3 x 3 + 2 ,   3 x 4 + 2 and   3 x 5 + 2 is equal to

Correct answer

6

Step-by-step solution

Variance of 3 x i + 2 = 9 v a r ( x i ) = 9 ∑ x i 2 5 - ∑ x i 5 2 = 9 5 - 1 = 36 ⇒ S . D = 6

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