Question

Mean of 8 observation was found to be 8 Later on it was found that one observation had been wrongly written as 13 in place of 10 Find the correct mean of observation ​

Answer 1

$\sf\huge\bold{Answer:}$

Given :

Mean of 8 observations = 8

Observation wrongly written

13 in place of 10

To find :

Correct mean

Solution :

Let original sum be x

Decrease in sum = 13-10 =3

New sum = x-3

Mean=sum of observation/no. of observations

8=sum/8

8×8=x-3

64=x-3

x=64+3

x=67

New sum is 67

Correct mean = 67/8 = 8.62

correct mean of observation is 8.62