# Mean of 25 observation was found to be 78.4 but later it was detected that 96 was misread 69 find the true mean

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by goyfcjk

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by goyfcjk

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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