The 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 & explanation
Correct answer: option 3
Sum of average marks of 25 students = 25 x 19 = 475
Sum of marks after correction = 475 - 18 - 19 + 14 + 15 = 467
New actual average marks of class = 18.68