Statisticshard · Past Paper
The mean age of a group of 100 people was 30. Later it was discovered that age 45 was misread as 25. The correct mean is:
A30.2
B30.5
C29.8
D31.0
✓ Correct Answer: A — 30.2
Difference = 45 - 25 = 20. Total sum increases by 20. Increase in mean = 20 / 100 = 0.2. New Mean = 30 + 0.2 = 30.2.
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