InterviewSolution
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InterviewSolution
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Find the mean and variance for each of the data :First 10 multiples of 3. |
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Answer» First 10 multiples of `3=3,6,9,…………30` Their sum `=sumx_(i)=3+6+9+…….+30` `=3(1+2+3+..+10)` `=3xx(10xx11)/2=165` Their mean `=(sumx_(i))/n=165/10=16.5` Sum of their squares `sumx_(i)^(2)=3^(2)+6^(2)+9^(2)+……+30^(2)` `=3^(2)(1^(2)+2^(2)+3^(2)+.....+10^(2))` `=9xx(10xx11xx21)/6=3465` Now variance `sigma^(2)=(sumx_(i)^(2))/n-((sumx_(i))/n)^(2)` `=3465/10-(16.5)^(2)` `=346.5-272.25=74.25` |
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