InterviewSolution
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InterviewSolution
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The mean of nine numbers is 77. If one more number is added to it, then the mean increases by 5. Find the number added in the data. |
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Answer» Mean = \(\cfrac{The\,sum \,of \,all \,observations}{Total \,number \,of \,observations}\) ∴ The sum of all observations = Mean x Total number of observations mean of nine numbers is 77 ∴ sum of 9 numbers = 11 x 9 = 693 …(i) If one more number is added, then mean increases by 5 mean of 10 numbers = 77 + 5 = 82 ∴ sum of the 10 numbers = 82 x 10 = 820 …(ii) ∴ Number added = sum of the 10 numbers – sum of the 9 numbers = 820 – 693 … [From (i) and (ii)] = 127 ∴ The number added in the data is 127 |
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