InterviewSolution
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InterviewSolution
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Let a, b, c, d, e, be the observations with m and standard deviation s.The standard deviation of the observations a+k, b+k, c+k, d+k, e+k is`s`(b) `k s`(c) `s+k`(d) `s/k`A. ksB. 2C. s+kD. `(s)/(k)` |
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Answer» Correct Answer - B Given observations are a, b, c, d and e. Mean `=m=(a+b+c+d+e)/(5)` `sum x_(i)=a+b+c+d+e=5 m` New mean `=(a+k+b+k+c+k+d+k+e+k)/(5)` `=((a+b+c+d+e)+5k)/(5)=m+k` `therefore S.D. =sqrt((sum(x_(i)^(2)+k^(2)+2kx_(i)))/(n)-(m^(2)+k^(2)+2mk))` `=sqrt((sum x_(i)^(2))/(n)-m^(2)+(2k sum x_(i))/(n)-2mk)` `=sqrt((sum x_(i)^(2))/(n)-m^(2)+2km-2mk)" " [because (sum x_(i))/(n)=m]` `=sqrt((sum x_(i)^(2))/(n)-m^(2))` =s |
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