The mean marks of 100 students were found to be 40. Later on, it was discovered that a score of 53 was misread as 83. Then, what will be the correct Mean?
Here,
Mean = Sum of marksNumber of students
∵ Mean = 40 [given]
and number of students = 100
∴ Total number of marks =40×100
=4000
The correct sum of observations
=4000+53−83=4000−30=3970
∴ Correct mean =3970100=39.7