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MHT CET20244 May 2024Evening ShiftMathematicsStatisticsActual

The mean and variance of seven observations are 8 and 16 respectively. If 5 of the observations are 2,4,10,12,14 , then the square root of product of remaining two observations is

Options

  1. A4 3
  2. B3 3
  3. C2 3
  4. D5 3

Correct answer

A. 4 3

Step-by-step solution

Let the unknown numbers be x and y . aligned & Mean =8 & 2+4+10+12+14+x+y 7 =8 & x+y=14...(i) & Variance =16 & 2^2+4^2+10^2+12^2+14^2+x^2+y^2 7 aligned -( mean )^2=16 aligned & 460+x^2+y^2=7 [16+(8)^2 ] & 460+x^2+y^2=560 & x^2+y^2=100 ...(ii) aligned Solving (i) and (ii), we get array ll & x=6, y=8 or x=8, y=6 & Product =48 & Product = 48 = 4 3 array

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