Mean of the 7 numbers = 12.0 Total of the 7 numbers = 12.0 x 7 = 84
Mean of the 8 numbers = 12.5 Total of the 8 numbers = 12.5 x 8 = 100
The 8th number is 100 - 84 = 16
--------------------------------------------------------------------- Answer: The new number is 16. ---------------------------------------------------------------------