The mid-point is basically the average of the coordinates. So for the x coordinate do (1+(-7))/2=-3. and for y, do (-10+7)/2=-3/2
This gives you the midpoint as (-3,-3/2)
Yes, as x(y) increase when y(x) increases , they are proportional.
(1,-2) hope this helps you :)
Check the picture below. Recall your SOH CAH TOA.
