Question
Download Solution PDFThe average of the marks of 25 students in a class, in an examination was calculated to be 19. Later, the teacher realized that the marks of two students were taken as 18 and 19 respectively, instead of 14 and 15. Find the new actual average marks of the class.
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven:
The average of the marks of 25 students in a class, in an examination was calculated to be 19.
Wrong marks are 18 and 19
Correct marks are 14 and 15
Concept used:
Average = Sum of elements/Number of elements
Calculation:
Total marks of 25 students with wrong numbers = 25 × 19
⇒ 475
Correct total = 475 - (18 + 19) + 14 + 15
⇒ 475 - 37 + 29
⇒ 467
So, new average = 467/25
⇒ 18.68
∴ The new actual average mark of the class is 18.68.
Last updated on Jul 19, 2025
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