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Mean of 100 items is 49. It was discover...

Mean of 100 items is 49. It was discovered that three items which should have been `60, 70,80` were wrongly read as `40, 20, 50` respectively. The correct mean is. (a) `48` (b) `82 1/2` (c) `50` (d) `80`

A

48

B

82.5

C

50

D

80

Text Solution

Verified by Experts

The correct Answer is:
C
Sum of 100 items `=49xx100=4900`
Sum of items added=60+70+80=210
New sum =4900+210-110=5000
`therefore " Correct mean" =(5000)/(100)=50`
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