Verifying your queries I've obtained the following error:
Looking back in the documentation we can see this:
ST_Distance_Sphere — Returns linear distance in meters between two lon/la points
That means the first coordinate for a point must be the longitude, and the second the latitude.
Therefore you'll have the following, properly, coordinates for your locations:
(-82.60, 33.44) -- location near Warrenton, GA
(-82.517, 33.533 -- locaton near Thomson, GA
(-97.361, 32.819) -- location near Forth Worth, TX
Now, let's run the queries again:
select st_distance_sphere(
st_setsrid(st_makepoint(-82.60, 33.44), 4326), -- location near Warrenton, GA
st_setsrid(st_makepoint(-82.517, 33.533), 4326) -- locaton near Thomson, GA
)
Result: 12891.3730143974 meters
= 8.01 miles
select st_distance_sphere(
st_setsrid(st_makepoint(-82.60, 33.44), 4326), -- location near Warrenton, GA
st_setsrid(st_makepoint(-97.361, 32.819), 4326) -- location near Forth Worth, TX
)
Result: 1375107.45231354 meters
= 854.45 miles