The mean and standard deviation of 20 observations are found to be 10 and 2, respectively. One rechecking, it was found that an observation 8 was incorrect. Calculate the correct mean and standard deviation in each of the following cases. (i) If

Explanation

`bar x = (sum x_i)/n = 10 = (sumx_i)/20`

`sumx_i= 200`

for 19 terms `= 200-8 = 192 = sumx_i`

`sigma = sqrt(1/n*sumx_i^2 - ( bar x )^2)`

let incorrect sum be `e sum`
`2 = sqrt(1/n* e sum x_i^2 - 100)`

`4 = 1/20 e sumx_i^2 - 100`

`e sum x_i^2= 104*20 = 2080`

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