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If the variance of the frequency distribution array |c|c|c|c|c|c|c| x & c & 2 c & 3 c & 4 c & 5 c & 6 c f & 2 & 1 & 1 & 1 & 1 & 1 array is 160, then the value of c N is

Options

  1. A7
  2. B8
  3. C5
  4. D6

Correct answer

A. 7

Step-by-step solution

array |c|c|c|c|c|c|c| x & C & 2 C & 3 C & 4 C & 5 C & 6 C f & 2 & 1 & 1 & 1 & 1 & 1 array x = (2+2+3+4+5+6) C 7 = 22 C 7 aligned & Var (x)= c ^2 (2+2^2+3^2+4^2+5^2+6^2 ) 7 & - ( 22 c 7 )^2 & = 92 c ^2 7 - c ^2 484 49 & = (644-484) c ^2 49 = 160 c ^2 49 & 160= 160 c ^2 49 c =7 aligned

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