Given :   A graph with points (1, 3), (2, 7), (3, 8), (4, 11), (5, 12), (6, 13).
To find :  From Which two points the line of best fit goes through
Solution:
(3, 8) &  (5, 12) will be two points
as then line  points will be
( 1 ,  4 ) , ( 2, 6) , ( 3 , 8 ) , ( 4, 10) , (5 . 12)  & ( 6 , 14)
(1, 3)   will be below ( 1 ,  4 )
(2 , 7) will be above ( 2 , 6)
( 3 , 8 ) will be on line
(4 , 11 ) will be above ( 4 , 10)
( 5 , 12  ) will be on line
( 6 , 13)  will be below ( 6 ,  14 )
(1, 3)  & ( 6 , 13)  two points are below line
(2 , 7) & (4 , 11 )  two points above line
Hence points are Equally scattered above  & below line
Hence (3, 8) &  (5, 12) will be two points on   line of best fit
Hope it helpss !!