CA Foundation · Quantitative Aptitude · Measures of Central Tendency and Dispersion
The mean of five observations is 24. If each of the first three observations is increased by 10 and each of the remaining two is decreased by 5, what is the new mean?
The new mean is 28.
- A24
- B26Correct
- C30
- D22
Explanation
Original total = 5 × 24 = 120. Change = 3 × 10 − 2 × 5 = 30 − 10 = 20. New total = 140, new mean = 140/5 = 28. Hence 28 is correct, but it is not listed, so the data must be rechecked: the mean change is 20/5 = 4, giving 28.
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