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Question
The mean of marks scored by 100 students was found to be 40. Later on it was discovered
that a score of 53 was misread as 83. Find the correct mean.
Solution
Mean marks of 100 students = 40
⇒Sum of marks of 100 students 100×40×4000
Correct value 53.
Incorrect value 83.
Correct sum = 4000-83+53
= 3970
∴ Correct mean =`3970/100`
= 39.7
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