Same chapter4 marksDifficulty: Hard
The mean of the numbers 12, 15, x, 20 and 25 is 18. Find x.
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4 marksDifficulty: Hard
The mean of 20 observations is 25. It was later found that an observation recorded as 40 should have been 60. Find the corrected mean.
Original Khojo Papers practice question — not from a past board paper.
Answer
26
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The recorded total is 500 and the corrected total is 500 − 40 + 60 = 520, so the corrected mean is 520 ÷ 20 = 26.
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