Answers

2016-04-30T10:05:27+05:30
Let the 25 observations be x₁,x₂,x₃......x₂₅
By the problem,
(x₁+x₂+x₃+...+x₂₅)/25=78.4
⇒x₁+x₂+x₃+....+x₂₅=78.4×25
⇒x₁+x₂+x₃+....x₂₅=1960------------(1)
Given that 96 was misread as 69
⇒96-69=27
So,x₁+x₂+x₃+.....x₂₅=1960+27=1987
It means,sum of observations is 1987
Now,mean=sum of observations/no.of observations
⇒1987/25
⇒79.48
Therefore,the correct mean is 79.48 .

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