Question

How would you solve this problem. The mean of 10 numbers is 8. If an 11th number is now included, the mean becomes 9. What is the value of the 11th number? Make an algebraic solution.

Answer 1

mean = ∑x/n

9 = (10*8 + x)/11

Solve for x.

Answer 2

1.237

Answer 3

19