Well, this is solved by a simple way
To find out midway, you have to first find the amount in between to 2 numbers
So, take 115-70, and you get 45
Well, it wants midway, meaning you'll be finding whatever half of the 45 is first. So, take 45/2 and you get 22.5
Well, now you have what half of the difference is, so all that's left is to add the 22.5 back to the 70
22.5+70=92.5
Your answer Midway between 70 and 115 is 92.5