Given That M is the midpoint of AW, which means M is half way between A and W;
Then it is given that;
Which means that A is between M and G; we can modify the sketch to;
The correct arrangement is either GAMW or WMAG depending on the direction you are moving from..
since;
A - Adams
G - Greensburg
M - Middleton
W - Waldron.
The correct arrangement is;
Greensburg, Adams, Middleton, Waldron.