Statistics · JEE Main previous year questions

2009 2 questions

1. Q202009 · 27 Apr 2009 · Shift 1

   If the mean deviation of numbers 1, 1 + d, 1 + 2d,........, 1 + 100d from their mean is 255, then d is equal to

   1. A.20.0
   2. B.10.1
   3. C.20.2
   4. D.10.0
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   Answer: B

2. Q212009 · 27 Apr 2009 · Shift 1

   Statement - 1 : The variance of first n even natural numbers is $\frac{n^2-1}{4}$ Statement - 2 : The sum of first n natural numbers is $\frac{n(n+1)}{2}$ and the sum of squares of first n natural numbers is $\frac{n(n+1)(2n+1)}{6}$

   1. A.Statement-1 is true, Statement-2 is true; Statement-2 is a correct explanation for Statement-1
   2. B.Statement-1 is true, Statement-2 is true; Statement-2 is not a correct explanation for Statement-1
   3. C.Statement-1 is true, Statement-2 is false
   4. D.Statement-1 is false, Statement-2 is true
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   Answer: D