SOLUTION: The average (arithmetic mean) of seven numbers is 7. When an eighth number is added, the average of the eight numbers becomes 8. What is the eighth number?

SOLUTION: The average (arithmetic mean) of seven numbers is 7. When an eighth number is added, the average of the eight numbers becomes 8. What is the eighth number?

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Question 753994: The average (arithmetic mean) of seven numbers is 7. When an eighth number is added, the average of the eight numbers becomes 8. What is the eighth number?
Answer by Cromlix(4381) (Show Source): You can put this solution on YOUR website!
Total of seven numbers = 7 * 7 = 49
Total of eight numbers = 8 * 8 = 64
Eighth number = 64 - 49 = 15
Hope this helps
:-)
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