class 11

Math

Algebra

Statistics

Out of 30 observation 10 are $21 +d,10$ are $21 $ and other $10$ are $21 −d$ whose variance is $34 $ then $∣d∣$ is equal to (A) $1$ (B) $2 $ (C) $3 $ (D) $2 1 $

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Consider the numbers 1,2,3,4,5,6,7,8,9,10. If 1 is added to each number, the variance of the numbers so obtained is (a) 6.5 (b) 2.87 (c) 3.87 (d) 8.25

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