I have a question about working with the coordinates system (and I hope I'm explaining this coherently). Basically, I need to make sure that I am properly calculating the exact distance between two Lat/Long points so that I can figure out the point that is exactly half way between the two points. First, I am converting to the decimal system to make the calculations easier. Therefore, the point (Lat N*41 52.0399  Long W87*16.4099) would be (Lat 41.8973 Long -87.2735) in decimal format.

Given the two points of (Lat 41.8673 Long -87.2735) and (Lat 41.8673 Long -87.2599) I believe that the exact midway point would be (Lat 41.8673 Long 87.2667). Since the Lat values are the same, the midway point between the two Long values would represent the midway point between the two coordinates.

How would I figure out the midway point between (Lat 41.9665 Long -87.2664) and (Lat 41.9650 Long -87.2508) . In this case, neither the Lat nor Long tracks match up.

The longitude values are negative numbers since this is the western hemisphere, but is it OK to disregard the sign?

Thank you very much;
Christine