Yes, I believe the answer is in the "vertical curve" section 5.3.2 has something in there I wouldn't quite understand it lol
I am thinking on how to split the easement gradient into a 1 in value so it be easier to understand them
If my calculations are correct starting with the previous grade of 1 in 30 and then I think it would be
1 in 40, 1 in 50, 1 in 100, LEVEL, 1 in 100, 1 in 50, 1 in 40 and then the 1 in 43 they are just a fair guess as to how easement gradients are calculated into a 1 in value by splitting it into sections as shown below
What do you guys think? If I am not correct that's fine but it be a fair guess if it is
Going back to my pure and applied maths at uni it is a very simple exercise. You have decided (why I don't know) to split the easement into 7 segments (n = 7). You could choose any number of segments you wish between 1 and infinity. An infinite number of segments will give you a constantly changing gradient (don't go there, it's called calculus). Going from one segment to the next each change will share an equal portion of the total change between 1:30 and -1:43 (note the - sign which signifies downhill instead of uphill), that is 8 changes in gradient (n+1).
For ease of calculation I have converted the gradients into percentages (US term for gradient), 1:30 is 3.33%, -1:43 is -2.33% (to two decimal places). Thus with eight changes in gradient each changes is -0.707% (to 3 decimal places). Converting back from percentages to 1:g we get: -
1:30, 1:38, 1:52, 1:83, 1:198, -1:491, -1:110, -1:62, -1:43 (all to nearest whole number).
PS; You were mostly on the right track (pun intended).