InterviewSolution
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InterviewSolution
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Consider the numbers 1,2,3,4,5,6,7,8,9,10. If1 is added to each number, the variance of the numbers so obtained is6.5 (b) 2.87 (c) 3.87 (d) 2.87A. 6.5B. 2.87C. 3.87D. 8.25 |
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Answer» Correct Answer - D Given numbers are 1,2,3,4,5,6,7,8,9 and 10. If 1 is added to each number, then observations will be 2,3,4,5,6,7,8,9, 10 and 11. `therefore sum x_(i)=2+3+4+..+11` `=(10)/(2)[2xx2+9xx1]=5[4+9]=65` and `sum x_(i)^(2)=2^(2)+3^(2)+4^(2)+5^(2)+..+11^(2)` `=(1^(2)+2^(2)+3^(2)+..+11^(2))-(1^(2))` `=(11xx12xx23)/(6)-1=505` `therefore s^(2)=(sum x_(i)^(2))/(n)-((sum x_(i))/(n))^(2)=(505)/(10)-((65)/(10))^(2)` `=50.5-(6.5)^(2)` `=50.5-42.25` `=8.25` |
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