The mean of 18 recorded values was computed as 124, but it was later found that figures 46 and 82 were logged incorrectly instead of 64 and 28. What is the corrected mean for the 18 records___________?
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Answer: D. 122
Explanation
The correct sum is found by subtracting incorrect logged values and adding correct values. The revised total sum equals 2232 minus 128 plus 92 resulting in 2196. Dividing the corrected sum by the total count of 18 records yields 122. Total sum of records equals the number of items multiplied by the original mean. Original sum equals 18 multiplied by 124 which is 2232. Corrected mean equals the revised sum divided by the total number of records.
Data cleaning and error correction are crucial steps in statistical data analysis. Auditing financial records often requires recalculating means after identifying logging errors. Mean sensitivity to outliers and errors necessitates careful data verification. Choosing 123 represents an incomplete adjustment of the incorrect data entries. Choosing 137 results from adding the incorrect values instead of subtracting them. Choosing 121 miscalculates the arithmetic division of the revised total sum.
- Subject
- Mathematics
- Category
- Mathematics
- Topic
- —
- Difficulty
- medium
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