It is: (63+57)/2 = 60
It is: 48
It is: 75
42
There are lots of numbers between 63 and 720. Exactly halfway between them is 391.50, so that may be the answer you are looking for.
42
26.5
107
It is: (63+57)/2 = 60
73
66
66
It is: 48
All are composite except 61 and 67. Composite numbers: 60, 62, 63, 64, 65, 66, 68, 69, 70
It is: 75
42
Oh, dude, halfway between 17 and 63? That's like asking me to pick a favorite child - impossible! But, if you really want to know, it's 40. I mean, I could go into the whole math explanation, but let's be real, who really cares about that stuff anyway?