The mean of scores obtained by 50 students is found to be 79.5. Later on, it was found that the score of one student was read as 94 in place of 49 and the score of another student was read as 69 in place of 89. Find the correct mean.
Answer & explanation
Correct answer: option 3
mean of scores obtained by 50 students = 79.5
sum of scores obtained by 50 students = 79.5 * 50 = 3975
After rectification of score 94 to 49, sum = 3975-94+49 = 3930
After rectification of score 69 to 89, sum = 3930-69+89 = 3950
Correct Mean = 3950/50 = 79
The correct answer is Option (3) → 79