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Mean deviation of the series a 2 , a 2 + d , a 2 + 2 d , . . . . . . . . , a 2 + 2 n d from its mean is

Options

  1. An + 1 d 2 n + 1
  2. Bn d 2 n + 1
  3. Cn n + 1 d 2 n + 1
  4. D2 n + 1 d n n + 1

Correct answer

C. n n + 1 d 2 n + 1

Step-by-step solution

mean x ¯ = 2 n + 1 2 · a 2 + a 2 + 2 n d 2 n + 1 = a 2 + n d Σ x — x ¯ = 2 d 1 + 2 + … … + n = n n + 1 d ∴ M · D · = n n + 1 d 2 n + 1

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