The proposal that called for a two house legislature with one house having equal representation for each state and the other having representation based on population was the
The Constitutional Convention's agreement to establish a two-house national legislature, with all states having equal representation in one house and each state having representation based on its population in the other house.
Since the graph is a linear function, we're going to use the slope formula solve this:
Note I am replacing m with k

Inserting 2 points from the graph, let's use (1,8) and (2,16).

k=8
Theorem
In a triangle, the measure of an exterior angle equals the sum of the measures of its two remote interior angles.
x + y = z
4n - 18 + n + 8 = 133 - 6n
5n - 10 = 133 - 6n
11n = 143
n = 13
z = 133 - 6n = 133 - 6(13) = 133 - 78 = 55
Answer: C. 55