Longitude and latitude analysis

The longitude and latitude change distance is as follows ：
change 1 degree ： Change distance 111km
1 branch ：1.6km
1 second ：30.8m

Longitude and latitude	Minutes and seconds
28.96885	28 degree 58 branch 7.86 second
28.96886	28 degree 58 branch 7.89 second
28.96887	28 degree 58 branch 7.93 second
28.96888	28 degree 58 branch 7.96 second

Conclusion ： About the third 5 One decimal place changes by one , Actual position change 1m