It is (12 + 13)/2 = 25/2 = 12.5 or 12½
19
The number halfway between 13 and 41 is 27.
2713 + 41 = 5454 / 2 = 2727 is halfway between 13 and 41.
It is (12 + 13)/2 = 12.5
11
13
it is: 22
It is 13
18.5
It is 13, the number halfway between the two middle numbers.
(13 + 23)/2 = 18
34