The mean of 50 observations was recorded as 36. Correcting an erroneous observation of 23 (should be 48) gives what new mean___________?
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Answer: C. 36.5
Explanation
Subtracting twenty three from forty eight reveals a net addition of twenty five to the sum. Distributing twenty five evenly across fifty observations increases the average by zero point five. Adding zero point five to the initial mean of thirty six gives thirty six point five. The arithmetic mean represents the sum of all observations divided by the total count. Correcting a single data entry changes the overall sum without altering the observation count. Linear properties of averages allow adjusting the mean directly using the correction delta.
Data scientists frequently correct erroneous records in large datasets before performing statistical analyses. Quality control inspectors adjust summary metrics when measurement errors are discovered during testing. Financial auditors update reported earnings per share after correcting historical accounting discrepancies. Option a represents a mistaken subtraction rather than addition of the correction value. Option b reflects an incorrect distribution divisor when spreading the difference across observations. Option d assumes a much larger correction delta than the actual arithmetic difference.
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- Mathematics
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- Mathematics
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- —
- Difficulty
- medium
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