Question

The mean of marks scored by 100 students was found to be 40. Later on it was discovered that a score of 53 was misread as 83. Find the correct mean.

Answer 1

Mean marks of 100 students = 40

Sum of marks of 100 students = 100 * 40

= 4000

Correct value = 53

Incorrect value = 83

Correct sum = 4000 – 83 + 53

= 3970

Therefore, correct mean \(=\frac{3970}{100}\)

= 39.7