The average of 19 numbers is 48. The average of the first 7 numbers is 50.6 and that of the last 13 numbers is 47.6. If the 7th number is excluded, then what is the average of the remaining numbers (correct to one decimal place)?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 47.3.
The average of 19 numbers is 48.
So, the sum of the 19 numbers = 48 × 19 = 912
The average of the first 7 numbers is 50.6.
The sum of the first 7 numbers = 50.6 × 7 = 354.2
The average of the last 13 numbers is 47.6.
The sum of the last 13 numbers = 618.8
7th number = (354.2 + 618.8) - 912 = 61
Required average = (912 - 61)/18 = 47.27 = 47.3