The x-value increases by a factor of 5 from 1.6 to 8 between the two points. Because the variation is inverse, the y-value must decrease by a factor of 5 between the two points.
6/5 = 1.2
The second point is (8, 1.2), corresponding to the 4th selection.
6/5 = 1.2
The second point is (8, 1.2), corresponding to the 4th selection.