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Mean of 10 items was found to be 15. On verification it was found that an item 21 was miscopied as 12. Find the correct mean.
$\begin {array} {1 1} (A)\;15 & \quad (B)\;15.3 \\ (C)\;15.9 & \quad (D)\;15.20 \end {array}$
jeemain
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cbse
class11
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measures-of-dispersion-(mean)
q53
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asked
Jan 25, 2014
by
thanvigandhi_1
retagged
Sep 7, 2014
by
sharmaaparna1
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1 Answer
Ans : (C)
Observed sum of 10 items = $ 15 \times 10$
$ = 150$
Corrected sum = $ 150 -12 + 21$
$ = 159$
Correct mean = $ \large\frac{159}{10}$
$ = 15.9$
answered
Jan 25, 2014
by
thanvigandhi_1
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