The average marks of 40 students in an examination was 25. It was later found that the marks of one student had been wrongly entered as 73 instead of 37. What is the value of correct average?
1). 24.3
2). 24.1
3). 24.5
4). 24.7
Given that average marks of 40 students is 25
⇒ Sum of marks of 40 students/40 = 25
⇒ sum of marks of students = 40 × 25 = 1000
According to the problem statement, correct average can be given as
⇒ (1000 – 73 + 37)/40 = 964/40 = 24.1
∴ the correct average marks are 24.1