The average (arithmetic mean) of a set of seven numbers is 8. When an eighth number is added to the set, the average of the eight numbers is still 8. What number was added to the set?
A. 6
B. 7
C. 8
D. 9
Answer:C
The average (arithmetic mean) of a set of seven numbers is 8. When an eighth number is added to the set, the average of the eight numbers is still 8. What number was added to the set?
A. 6 B. 7 C. 8 D. 9