CMA Foundation · Fundamentals of Business Mathematics and Statistics · Measures of Central Tendency and Dispersion
The mean monthly wage of 40 workers in a Coimbatore unit is ₹18,000. Later it is found that one worker's wage of ₹21,000 was wrongly recorded as ₹12,000. What is the corrected mean wage?
The corrected mean wage is ₹18,225. The wrong total was 40 times 18,000, or 7,20,000. Replacing 12,000 with 21,000 adds 9,000, giving 7,29,000, and dividing by 40 workers yields 18,225. The mean is affected by every value.
- A₹18,225Correct
- B₹18,000
- C₹17,775
- D₹18,450
Explanation
Wrong total = 40 × 18,000 = 7,20,000. Correction = 21,000 − 12,000 = +9,000, so the correct total = 7,29,000. Corrected mean = 7,29,000/40 = ₹18,225. The mean stays at 18,000 only if the error is ignored, which is wrong.
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