Question

the mean (average) of 6, 9 and 18 is equal to the mean (average) of 12 and $y$. what is the value of $y$?

Answer 1

3

6+9+18

=

2

12+y

3

33

=

2

12+y

11=

2

12+y

22=12+y

10=y

answer: 10=y

Answer 2

y = 10

Explanation:

`\displaystyle (6+9+18)/(3)=(12+y)/(2)\\ \\(33)/(3)=(12+y)/(2)\\ \\11=(12+y)/(2)\\ \\22=12+y\\\\10=y`