Answer:
C(x)=1.76067x - 331.98
Explanation:
We are given two points (x,y) of the linear function C(x):
P1 = (200; 20.15) and P2 = (500; 548.35)
The slope of the function, 'm', can be found by:

Applying point P1 to the general linear equation gives us C(x):
