InterviewSolution
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InterviewSolution
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The mean of data is 10. If each observation is multiplied by 2 and 1 is subtracted from each result, the mean of the new observation is ……A) 21 B) 19 C) 9 D) 10 |
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Answer» Correct option is: B) 19 Given that the mean of data is 10. Let number of observations be n \(\therefore\) Sum of original observations is \(\sum x_i = 10n\) ...(1) Given that each observation (\(x_i\)) is multiplied by 2 and 1 is subtracted from each result. \(\therefore\) New observations are of type (2\(x_i\)-1). Sum of new observations = \(\sum\) (2\(x_i\)-1). = 2\(\sum\)\(x_i\) -\(\sum\) 1 = 20n - n (\(\because\) \(\sum\)\(x_i\) = 10n & \(\sum\) 1 = n) = 19 n \(\therefore\) Mean of new observations = \(\frac {sum \, of \, new\,observations}{ number \, of\, observations}\) = \(\frac {19n}{n} = 19\) Hence, the mean of new observations is 19. Correct option is: B) 19 |
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