Same chapter4 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.
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4 marksDifficulty: Hard
The mean of the numbers 12, 15, x, 20 and 25 is 18. Find x.
Original Khojo Papers practice question — not from a past board paper.
Answer
18
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The sum must be 5 × 18 = 90. The known values total 72, so x = 18.
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