The average score of 40 students in a class test in 45. Later on, it was found that at two places 25 was read as 35 and at one place 38 was read as 32. What is the actual average score of the class?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e 44.65.
One knows that,
Average = (sum of observation)/(number of observation)
So one can say that, Sum of observations = Average × number of observation
Sum of the score of 40 students = 45 × 40 = 1800.
Correct sum of marks of 4 students = 1800 - 35 - 35 - 32 + 25 +25 + 38 = 1786
Correct average marks of four students = 1786/4 = 44.65.