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The numbers 4 and 9 have frequencies x and (x-1) respectively. If their arithmetic mean is 6 , then what is the value of x ?

Options

  1. A2
  2. B3
  3. C4
  4. D5

Correct answer

B. 3

Step-by-step solution

Arithmetic mean = Sum of data Number of data aligned & 6= 4 x+9(x-1) (x+x-1) & 6(2 x-1)=4 x+9 x-9 & 12 x-6=13 x-9 & x=9-6=3 . aligned

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