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AP EAMCET201822 Apr 2018Morning ShiftMathematicsStatisticsActual

The mean and the standard deviation of a data of 8 items are 25 and 5 respectively. If two items 15 and 25 are added to this data, then the variance of the new data is

Options

  1. A29
  2. B24
  3. C26
  4. D29

Correct answer

A. 29

Step-by-step solution

We have, n=8, x =25 and =5 aligned & x = x_i n & x_i=n x =8 25=200 & In corrected x_i=200 & and =5 & ^2=25 & 1 n x_i^2-( mean )^2=25 & x_i^2 8 -625=25 & x_i^2=5200 & Corrected x_i^2=5200+225+625=6050 & and corrected mean =200+15+25=240 & Corrected variance = 6050 10 - ( 240 10 )^2 & =605-(24)^2=605-576=29 & aligned

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