InterviewSolution
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InterviewSolution
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The mean of 23 observations is 34. If the mean of the first 12 observations is 32 and that of the last 12 observations is 38, find the 12th observation. |
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Answer» Let the 12th observation be x Given that mean of 23 observations = 34 ∴ sum of 23 observations = 23 × 34 = 782 Mean of the first 12 observations = 32 Sum of first 12 observations = 12 × 32 = 384 Mean of the last 12 observations = 38 Sum of the last 12 observations = 12 × 38 = 456 Therefore, Sum of first 12 observations + sum of last 12 observations – 12th observation = sum of 23 observations 384 + 456 - x = 782 ⇒ 840 – x = 782 ⇒ x = 58 |
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