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The mean marks of 30 students in a class is 58.5. Later on, it was found that 75 was wrongly recorded as 57. Find the correct ones.

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The mean mark of 30 students in a class is 58.5. Later on, it was found that 75 was wrongly recorded as 57. Find the correct ones.
A. 57.4
B. 57.5
C. 58.9
D. 59.1

View Answer
D. 59.1

Correct mean = 30x 58.5 -57 +75/30
= 1755+18/30 = 1773/30 = 59.1