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The mean of 200 items was 50. Later on, it was discovered that the two items were misread as 92 and 8 instead of 192 and 88. Find the correct mean. |
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Answer» Given n = Number of observations = 200 Mean = sum of observations/ number of observations 50 = sum of observations/ 200 Sum of the observations = 50 x 200 = 10,000. Thus, the incorrect sum of the observations = 50 x 200 Now, The correct sum of the observations = Incorrect sum of the observations – Incorrect observations + Correct observations Correct sum of the observations = 10,000 – (92 + 8) + (192 + 88) Correct sum of the observations = 10,000 – 100 + 280 Correct sum of the observations = 9900 + 280 Correct sum of the observations = 10,180. Therefore correct mean = correct sum of the observations/ number of observations = 10180/200 = 50.9 |
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